You are here

Unity of knowledge


I. The Aspiration towards a Unity of Knowledge: Grounds and Uncertainties. 1. Expressions of Contemporary Trends: towards an Integrated Knowledge. 2. Difficulties and Perplexities in proposing once more a Synthesis of Knowledge. 3. The Persisting Desire for Unity on the Intellectual and Existential Levels. - II. Attempts to Unify Knowledge: Models in History and Philosophy. 1. The Classic Ancient World and the “Novelty” of Christian Revelation. 2. The Universities in the Middle Ages and the Work of Thomas Aquinas. 3. Projects of Unification in the Modern Age. - III. Interdisciplinarity and Dialogue between Different Fields of Human Culture: does a University Campus still exist? - IV. The Search for Unity in Reflecting upon the Object: Beyond the Interdisciplinary Approach. - V. The Building of Unity inside the Subject: the Unity of Knowledge as Listening to, as Habitus and as Act of the Person - VI. The Unity of Knowledge and the Unity of the Mind of Believers. 1. Faith and Reason in the Unity of the Person. 2. Unity of Knowledge and Unity of Life.

The study of the relationship between scientific and humanistic knowledge, between empirical knowledge and philosophical wisdom —including in the last, the wisdom belonging to religious faith and originating in biblical Revelation— inevitably leads to the huge question about the possibility and conditions of a “unity of knowledge.” This question is generally raised on two different conceptual levels, apparently separate yet at the same time, connected to each other. The first concerns the integration between scientific and philosophical rationality. It involves gnoseology (the various levels of abstraction in our knowledge of reality), epistemology (the problems of the foundation and the truthfulness of scientific knowledge), but also anthropology (the answers to the “questions of meaning” experienced by the knowing subject). The second level concerns the integration between natural reason and religious faith, between “what I know” and “what I believe,” between philosophy, intended here in a broad sense, as knowledge obtained from listening both to nature and to the human conscience, and theology, a knowledge that originates from listening to the Word of God. Insofar as the above mentioned sources —scientific rationality, wisdom, philosophy, and faith in the revealed divine word— are all acknowledged as different forms of true knowledge, the subject asks for a certain agreement among them. Such an agreement is sought not only to let these ways of understanding coexisting peacefully, for instance noting that they concern different and not overlapping formal objects, but also to provide a kind of synthesis of their common material object, that is, reality. The agreement and the synthesis between different sources of knowledge is required by the subject especially to clarify and better orientate his or her own judgments and choices, in particular those belonging to the existential sphere.

Any meaningful discussion on the unity of knowledge, especially in what I have called “the second level” of integration, obviously implies overcoming agnosticism by giving a positive answer to the issue of truth and its unity, that is, by affirming that a truth exists and I can know it. This also implies the giving up of the Kantian inheritance concerning the division between “knowing” (Ger. erkennen, characterizing pure reasoning) and “thinking” or ethical postulation (Ger. denken, characterizing practical reasoning). It means to acknowledge that there is a reality which is, at the same time, a source of scientific knowledge, of ethical questioning, and of religious experience. In searching for such a synthesis, we must face the world without separating what the world is from what the world means. We must look at ourselves without separating the critical rationality of our own knowing from the responsibility implied in such knowing. Finally, it means to not separate the search for what makes a science true from the conditions that make a science good, thus having access to the ultimate reasons that may justify and support our “making science.”

My goal here is to investigate the modalities, in the past as well as in the present, in which the idea of unity of knowledge is presented, discussed, or sought. I also want to look at the main theoretical difficulties which such an approach brings about, as well as the epistemological and cultural incentives that support it. I will try to suggest which kind of anthropology is capable of inspiring a balanced foundation of such an intellectual synthesis, one meaningful in the contexts of university studies and of scientific rationality, which are experiencing today a highly specialized diversification of disciplines. We must also examine whether access to the religious level of knowing might represent an obstacle to such unification or, on the contrary, whether it might foster it. The inclusion of this last question is unavoidable for the believers’ thought, for without it any satisfactory synthesis would not be possible, neither at the intellectual nor at the existential level.

I. The Aspiration towards a Unity of Knowledge: Grounds and Uncertainties

In a number of cultural environments, the discussion of the unity of knowledge has again come up in debate, although in ways quite different from the past. Many authors emphasize the still existing contrast between the unity of knowledge as it was proposed by classical culture and then by the Christian Middle Ages (up to Humanism), and the diversification and fragmentation frequently alluded to characterizing the Modern Age. If such a fragmentation became evident with the development of the scientific experimental method, today the agenda of the so-called post-modern culture is precisely that of declaring the end of any unitary view. Science emphasizes the provisional dimension of its knowledge, while contemporary culture willingly endorses a pluralistic and relativist approach to the idea of truth. Following this trend, which very likely started with Francis Bacon (1561-1626), the ideal of wisdom was slowly replaced by the ideal of expertise, and the contemplation of nature by the will to analyze, manipulate and dominate the world.

Although such a historical-conceptual picture, at first sight, interprets quite well the common understanding of many, it must be pointed out that the 20th century brought about a new philosophical view. We need in particular to acknowledge what the epistemology of sciences has achieved since the 1930’s and 1940’s, and the raising of a new sensitivity that, from the 1980’s onward, has involved the relationship between the natural sciences and the human sciences, including a more delicate relationship between scientific and religious thought. Today many independent results suggest that the various fields of knowledge must remain “open,” that is, interrelated to each other, as each individual field seems to have recognized the impossibility of being epistemologically self-reliant.

1. Expressions of Contemporary Trends: towards an Integrated Knowledge. The implicit tendency of human knowledge towards unity takes different shapes. One of them is today’s re-discovery of interdisciplinarity. However, this is often understood in its “weak” aspect of simple multidisciplinarity, that, is a kind of “horizontal” approach favoring a better insight or representation of a certain object of study, the satisfactory knowledge of which cannot be carried out following a single method or discipline. At times, interdisciplinarity is understood and employed in its “strong” form, as meta-disciplinarity or trans-disciplinarity, that is to say, as a search for a “vertical” inter-dependency among different disciplines. In this latter case, methods and objects of a given discipline are read and understood in the light of a more general and basic language or knowledge, from which they implicitly assume, in a more or less conscious way, principles and models. As experimental progress goes in depth, it may happen that some new objects or properties discovered are recognized as belonging to a discipline other than the one we started with. Take for example what has happened in quantum mechanics, in elementary particle physics, and in the deeper understanding of chemical transformations and biological processes. The need to apply tools such as logic, statistics, or the theory of systems to subject matter which traditionally used heuristic principles, has favored the birth of new fields of research study, as well as the dialogue among already existing disciplines, overcoming, or at least shortening, the distances between the natural and human sciences. At times, the complexity of the object of study has suggested a coordinated multidisciplinary approach. This has been the case of physical systems that do not follow plain and predictable laws, of living organisms, of issues related to health, social, economical, or communication dynamics.

With regard to the “vertical” dimension of interdisciplinarity, two new tendencies are present today in science, which deserve to be mentioned here. The first is the propensity of  many scientists to offer “philosophical” reflections when considering some specific theoretical issues, such as problems of foundation in logic and mathematics, the question of the whole of reality and of its origin, the research on the mind-body problem, etc. The second is the greater willingness of scientists (or at least of a relevant percentage of them) to take into consideration what anthropology, philosophy, or even theology, could possibly have already said on issues near to one’s field of research. Here, the interdisciplinary thrust towards unity has taken advantage of a number of meaningful epistemological results, which put in light the limits of scientific observations, incompleteness of logic systems, and unpredictability of many physical phenomena, as something intrinsic to the specific methodology of a given discipline. In this way, interdisciplinarity as such is overcome (see below, IV) and we get closer to a kind of synthesis. More recently it has also been possible to see the surfacing of “new epistemologies” in an attempt to prepare the theoretical conditions necessary to successfully face the new need for analysis and predictability, thus exploring overlapping fields and welcoming common programs of study inconceivable in the past.

The desire for a form of knowledge that is more unitary also comes from a new image of science, or rather of the way of making science. The scientific enterprise is less and less considered as a completely “impersonal” and “objective” activity. On the contrary, this activity is now seen as more personal and self-involving (cf. Polanyi, 1958; Cantore, 1977). Today, scientific activity is better recognized as a “personal” activity. Of particular importance is the fact that such a personal dimension does not concern only ethics and/or aesthetics, but has consequences also on the epistemological level. The personal dimension of scientific knowledge obviously deals with the unavoidable relationship between subject and object in most experiment, but it also, and even more deeply, concerns those heuristic and silent factors of unexpressed knowledge (cf. Polanyi, 1983). These factors are precisely those which allow the acceptance or refusal of a given scientific result, due to the role of a number of philosophical pre-comprehensions belonging to the subject, which determine the way in which many scientific theories are created and expressed, as well as their duration and destiny within a given scientific community.

That scientific-experimental factors and humanistic factors are strictly tied to each other also emerges from the growing perception of ethical and moral issues, as if they were something intrinsic to scientists’ research activity, and not confined only to technological applications. The emergence of moral factors, however, should not be seen as a “limiting” or “conditioning” aspect of scientific activity, but can be accepted as the positive presence of a “surplus of humanism” hidden in the scientific undertaking. Indeed, scientific activity involves the researcher not only in the sphere of making, but also in that of being and meaning. That this last extent is clearly at work when scientists reflect on the motivations and the meaning of their own work, to the point of speculating about the “ultimate questions” regarding the knowledge of truth and the sense of human life in the universe. The philosophical perspective which has positively evaluated and emphasized the anthropological and existential dimensions of scientific activity is today known as “scientific humanism”, or, also, as philosophical reflections on the “humanist dimension of science” (a qualified summary of this perspective is offered by John Paul II, Discourse to the Pontifical Academy of Sciences, November 13, 2000).

We must also mention a further way in which the need to develop a more integrated vision of knowledge is recognized today. It is the awareness that all techno-scientific progress must be associated with a cultural progress; that material goods, education, professional training, and intellectual resources are all important for human progress, and they need to be made available all together. For this reason, not a few Organizations realize that the “technicians” responsible for projects of social interest must receive appropriate training also in humanistic disciplines or, at least, they need to be sensitive to this area. It is easy to realize that each aspect of research and development, from the mapping of the human genome to researching new energy programs, from the planning of a new hospital to the design of an urban area, requires a specific vision of mankind and society. Techno-scientific knowledge claims to be integrated with reflection of an ethical nature (cf. Gismondi, 1999) or, at least, with the collaboration of the human sciences. Issues such as bio-technologies, preservation of the environment or health care, have recently urged attention to this need. The cultural and religious inheritance of people and nations, whose influence on the consciences of billions of men and women, and on many aspects of social life, is, in this respect, crucial. And, as I will try to show below, a renewed reflection on the nature and mission of the University could also offer its specific and very valuable help (see below, III).

However, “scientific humanism” is not a concern shared by everyone, and the expression itself is subject to different, even contradictory, judgments. Some believe that the presence of “two cultures,” the scientific and the humanistic, each with its own logic unable to communicate with the other, is a too well-established intellectual situation to be easily overcome. Thus any serious program aiming at establishing a constructive dialogue is considered as illusory or rhetorical. The definitive separation of these fields of knowledge is considered to be a condition necessary to the maintenance of accuracy and rigor of the different methodological approaches. To support this thesis, people used to quote the first edition of the well-known essay by P.C. Snow, The Two Cultures (1959), in which the author provides a penetrating picture of Cambridge University in England in the 1950’s, disclosing a paradigmatic example of a general situation. Another view-point claims that in order to overcome the separation of these two cultures and develop a more mature way of thinking, a “third culture” should be fostered. According to this view, one should no longer appeal to science (in its traditional forms) or philosophy, or other forms of wisdom, including religion, in order to regulate human life and guide social choices. We should turn, instead, to a new culture made up of the values of science “taken as the true philosophy” (cf. J. Brockman, The Third Culture, New York 1995). My opinion is that the humanist value of science would, in this way, be misunderstood and dangerously transformed into the expression of a new scientism, as the “third culture” promoters reassure that science is capable of offering a consistent philosophical answer to all human, ethical and social problems. Neither Snow’s analysis —as it appears in his later reflections on the same subject in 1961 and 1964— nor the new epistemological results achieved by the natural sciences themselves, seem to suggest the reliability of a third culture, understood as a kind all-encompassing, philosophical vision of reality guided by science. The question is not that of asking science and technology for solving all human problems, but rather that of training scientists and technicians to have a humanistic sensitivity. The “two” cultures are not two opposite cultures, but rather two different sides of the same and unique human culture.

2. Difficulties and Perplexities in proposing once more a Synthesis of Knowledge. History shows us that the most important cultural expressions of all peoples and nations, from art to literature, from their vision of nature to their conception of humankind, have often embodied a good amount of “unified and coherent knowledge,” often induced by the impetus of philosophical and religious thought. Let us take, as examples, the “myths about the origins” of the first human cultures, the structure and the life of the Greek polis, the cathedrals and the Summae of the Middle Ages, the Encyclopedias of the Modern Age. Today, a similar unifying logic can perhaps be found only in the information technology of contemporary cabled societies, or in the increasingly extended logic of the global market. However, when compared to the above examples, these do not offer any real cultural “synthesis.” On the contrary, informatics and economy carry out the process of unification only on the utilitarian and pragmatic levels. If the stones of the refined architecture of the Gothic cathedrals used to express a patient and meaningful synthesis of faith, geometry, and philosophy, one inspired by the belief in everlasting truths and destined to a perpetual witnessing, today the bricks that make up the information technology network of the new economy simply provide a common language, one made of changing rules and provisional structures which can be built, and quickly razed, according to the needs of the moment.

The concept of the unity of knowledge today suffers some disenchantmentand raises a certain skepticism. Present situation is quite different from the past. The unity of knowledge built in the Middle Ages and guided by Christian theology was supported by a metaphysical convergence between “being” and “truth.” In other words, the varieties of knowledge about reality all allowed a common openness to the search for the ultimate and grounding causes. In the light of the “principle of creation,” all these causes were linked by a common hierarchical dependence of the whole of reality on God. This also implied the convergence towards a unique deeper truth having universal characteristics. Such a vision should today confront the crisis of the notion of truth, with respect to both the epistemological and the anthropological field. Moreover, the huge growth of the process of the specialization of knowledge caused by scientific progress, seems to have made unreal any attempt towards unification. Once the unity of knowledge is searched for or understood in this way, it seems very difficult to be put into practice. It is as difficult as thinking of the simultaneouspresence of several competencies, corresponding to a variety of scientific fields, in one person, institution or educational project. Finally, the notion of unity of knowledge seems to have been largely applied, in the past, by some “philosophical systems” built for the purpose of interpreting and unifying, in a coherent picture, theory and praxis. Search for unity might resemble a kind of approach as that rooted in the idealistic philosophies, aiming at compelling towards an a priori reading of all of reality, reducing it to an ideal system especially conceived to gain intellectual, political, religious or economic influence and power.

All these are quite serious objections that do not allow for an easy way out. However, with respect to the idea of the weakness of truth and the lack of trust in a knowledge that could lead to a unified vision of reality, we have to say that such a distrust also represents nothing but a philosophical vision itself. As such, it must confront reality, be subjected to rational criticism, justify its foundations, and prove it to be more legitimate than a vision which still believes that human knowledge is not wholly conventional nor merely functional, but instead capable of entering the realm of a universal truth. With respect to the impossibility of unifying knowledge in an irreversibly fragmented culture, the presence of some trends, which seem to indicate an evolution of things in the opposite direction (as discussed in this Section at nn. 1 and 3), must be also taken into account. Moreover, an important question should be here addressed: was the unity of knowledge abandoned when the fields of study began to grow and diversify, or, rather, when human beings lost their own intimate center, the awareness of their place in the cosmos? And, if so, what could bring back such a center and such awareness? With respect to the fear of undergoing ideological temptations when looking at reality with “unifying visions,” I will come back to this topic in the following Sections of this article (see below, V), discussing whether the intellectual path towards unity requires, as a first step, a “vision of” or, rather, a “listening to” reality.

3. The Persisting Desire for Unity on the Intellectual and Existential Levels. As we have seen, present times are not characterized by philosophical synthesis aimed at proposing a new unity of knowledge. According to most writers, among the elements characterizing the post-Modern Age there is the declared abandonment of “major narrations” (Fr. grand récits) or “cosmovisions”. Actually, it is interesting to note that such great, all-encompassing narrations seem to have moved today from the field of philosophy to that of science. Starting from the second half of the 20th century, the tendency has been towards attempting to propose unitary visions of reality, wanting to integrate the results of the natural sciences with the great themes of human existence, including the world of values and of spiritual experiences (intended here in a general sense). Scientists and researchers are often interpreters of such a new trend. In his essay Science and Humanism (1951), Erwin Schrödinger questioned the value of the natural sciences and concluded that their objectives, goals and values are the same as those of any other field of human knowledge. The general goal, Schrödinger adds, is nothing but obey to the divine rule carved into the temple door at Delphi: “know thyself.” Surprisingly enough, we find almost the same words in John Paul II’s Fides et Ratio (1998), when this document expresses disappointment over contemporary philosophy’s abandonment of major perennial themes, such as the search for truth and its uniqueness, the meaning of life, the quest on God, different from what ancient and modern philosophy did for many centuries, from its very beginning (cf. Fides et Ratio, nn. 1-5).

No wonder, then, that during the 20th century the most important metaphysical questions have been posed by scientists, not by philosophers. Why is it that many of the most renowned scientists belonging to the century of quantum mechanics, of the DNA double helix, and of the Big Bang, have felt the need to face questions on the relationship between philosophy and science, between science and religion? From Planck to Einstein, from Schrödinger to Heisenberg, from Wittgenstein to Eccles, all have tried to focus on the relationship between different forms of knowledge. Many of those who opened new scientific horizons also wanted to offer a corresponding philosophical interpretation of their results. So did, for example, Cantor, Planck, De Broglie, Heisenberg or Einstein, and more recently Feynman or Prigogine. Even those contemporary scientists who have generally maintained a critical attitude towards the life of the spirit and towards transcendence, such as Monod, Weinberg or Hawking, have not been able to avoid facing problems which are relevant also from a humanistic, not only scientific, point of view. Many others, whose names are too numerous to list here, have used their books of science popularization to convey reflections which go beyond the field of science to involve philosophical and even existential issues. A qualified indication of a new room for reflection on these subjects is the presence of chairs of “Religion and Science” now found in many universities, including the very prestigious Cambridge, Oxford, Princeton and Chicago (cf. Easterbrook, 1997).

If, on the one hand, such a state of affairs runs the risk of naive syntheses and often shows lack of theoretically mature proposals (absent or rare among scientists, and uncertain among philosophers), on the other hand it tells us about the need to link, in a less instinctive and more convincing way, the knowledge coming from scientific, philosophical and religious thought. In other words, there is a real will to “understand.” A fragmented culture is felt as a disease, not only at the intellectual level, but also at the existential level: the reality of a “unique” world is being reclaimed (cf. Polkinghorne, 1986). The call to mutual listening (cf. Haught, 1995), and subsequently towards a meaningful dialogue between disciplines so different from one another seems to indicate the strong desire for a synthesis that would go beyond a simple symbiosis (cf. Heller, 1986). The point is to see whether such a synthesis must rely on an exclusively subjective basis or, rather, whether there exists a common ground on which its research can be carried out. And to ask whether is science the only universal objective language or, instead, a meaningful language capable of involving also our common existential experiences beyond the boundaries of each individual subject may exist, something the canons of scientific formal language and methods are unable to express and disclose by alone.

II. Attempts to Unify Knowledge: Models in History and Philosophy

Many authors have provided presentations and evaluations of the various forms and projects of unity of knowledge throughout the history of thought. Here, my aim is to simply recall some of them within a short historical path.

1. The Classic Ancient World and the “Novelty” of Christian Revelation. Philosophy has made several attempts to carry out a conceptual unification of reality, which represents a first step towards a possible unification of knowledge. Authors of the classic ancient world tried to carry out such an endeavor by relying on the notion of “nature,” intended as an ordered whole, a kósmos from which everything comes and to which everything returns. In its empirical dimension, the unification of all reality was sought by taking as the point of departure a physical “principle” (Gr. arché), one or more common primordial elements (earth, air, water, fire...) from which the plurality and variety of things observed in nature could derive. In its rational dimension, reality was unified and reconstructed as if it were a single world of ideas and forms of divine origin. This was done by following the principles of mathematics and geometry, which were thought to belong to the sphere of the divine rather than to the material world. Slowly, classical thought developed this perspective, creating the philosophy of the logos. According to the Platonic approach, the logos was something transcending nature, while Stoicism considered it as a law immanent in nature itself. Thus, objects and knowledge are structured according to a hierarchic model, whose final goal was to maintain the order, proportion, and coherence of the whole.

When Christian Revelation made its entrance into the Greek-Roman world announcing the mystery of the Incarnated Logos, this did not bring any “theoretical” reflection on the unity of knowledge, but had, nevertheless, great resources and potentialities in this respect. Firmly anchored to the doctrine of creation and providence, already known in the Old Testament, the writings of the New Testament, especially those of St. Paul and St. John, announced the revelation of a radical source of unification. It is the divine project of God-Father to create and sum up in Christ, his beloved Son, all things in heaven and on earth, and through Him, reconcile all things, making peace by the blood of the cross. Thus, the Christian Logos embraced the categories of creation and alliance, the transcendence of God over everything and His intimate presence in human history. For the first time, the reasons of truth and the reasons of life, the demand of philosophical rationality and the hope of religious expectations were joined together. Aware of such philosophical richness, the Fathers of the Church developed a first example of a Christian unification process. In his anti-Gnostic writings, Irenaeus of Lyon demonstrated that God, the Creator of heaven and earth, was the same God who revealed Himself in Jesus Christ. The Greek apologists Theophilus of Antioch, Tatianus and Athenagoras, tried to persuade the pagans that the Provident God that they could come to know through nature, was the only God announced by the Christians. Emphasizing the uniqueness of one only God, good by nature, Augustine of Hippo overcame the split between good and evil maintained by Manichaeism, so depriving evil of any ontological basis. Evil was understood as a consequence of mankind’s free will, but something always under God’s power, Who is able to bring all things back to harmony with a love stronger than death.

2. The Universities in the Middle Ages and the Work of Thomas Aquinas. Christianity developed its first organic and structured project of unification of knowledge with the institution of the University in the Middle Ages. There, the varieties of knowledge were organized around theology, because of the special role this discipline had for the final goal of the human being and the common good of society as a whole. For the most part, the Christian synthesis of that time was based on Sacred Scripture and on the Auctoritates. This last term was intended to indicate the Christian classics, as well as pagan philosophers such as Aristotele and Plato. The philosophy of the latter was transmitted through Augustine and Pseudo-Dyonisus. Compared to theology, all the other disciplines played a subsidiary role, but it would be wrong to think that such a role was merely instrumental. The work of pagan philosophers, as well as the observation of natural phenomena available at that time, represented, in fact, a body of knowledge valued for its intrinsic importance. Authors of the Middle Ages used this knowledge to suggest key analogies between the book of nature and the book of Scriptures, to offer arguments to support the reasonableness of Christian beliefs, and to pose questions which prompted theology to elaborate new syntheses and more profound researches.

In this epoch, Christianity applied a new reading of the concept of Nature in light of the concept of Creation. In this way, the hierarchical scale of beings discussed in ancient philosophy was restored and now presented under a theological point of view: everything comes from God and returns to God. In harmony with the properties of the Christian Logos, this proposal of unification did not concern only the theoretical, but also included the existential level. The great Summae of the Middle Ages, which include Dante’s Divine Comedy are testimony to this cultural program. To use St. Bonaventure’s words (ca. 1217-1274), we are dealing here with the process of “leading the Arts into Theology.” Rational knowledge finds in theology a higher articulation and biblical Revelation provides us with new insights. “It is clear that all our learning is put to the service of theology, which draws examples and uses words from every field of knowledge. It is also clear how the road to the light is opened and how all things, heard or known, hide God intimately. This is the result of all sciences, because in them faith must be built, God honored, rules established for better behavior, the union of bride and bridegroom satisfied through charity. The Sacred Scriptures lead to charity, and, consequently, all enlightenment comes from Above. Without it [charity] all knowledge is in vain, because we will never reach the Son without the Holy Spirit, who teaches us all Truth and is blessed throughout the centuries. Amen.” (Reductio artium ad theologiam, n. 26). The disciplines other than theology did not undergo such a reductio as if they were limited by theology or dissolved into it. The idea of being reduced to theology had, rather, the meaning of “being brought back to,” or also that “of recognizing” its own truth. The truth about something became clearer by leading it back (Lat. re-cum-duco) to its own place in God’s design. The Creator’s design could be recognized (Lat. re-cognitum) from what has been created. Knowledge is “one,” not because it was made “one” by theology, but because creation and its Cause, studied by theology, are “one,” that is, unique.

The project of unification undertaken by Roger Bacon (1214-1292) in his Opus Maius was, in this respect, quite interesting. This work is a kind of ante litteram Encyclopedia, describing all the various fields of knowledge and their different methodologies. Bacon emphasizes the importance of bringing together, under the light of theology, all knowledge coming from the observation of nature. Observations should be made with a scientific mind, even with a sense of curiosity and of awe of the unknown. (Because of this approach, the Franciscan was charged with occultism). In addition to Vincent of Beauvais (ca. 1190-1264), the author of an encyclopedia of knowledge titled Speculus maius, many other writers such as Albert the Great, Robert Grossteste, Thomas Bradwardine, Nicolaus of Oresme, all were valued for their understanding of the sciences of that period as well as for their theology. They were all active in “re-conducting,” within the unitary and unifying horizon of their Christian faith, the knowledge coming from the various disciplines they were studying.

It is interesting to observe that the University was the place where the elaboration of most of the above mentioned attempts towards unification were carried out. For its depth and clarity of thinking, the figure of Thomas Aquinas (1224-1274) emerges in this academic context. His systematic approach was the result of the studies he ran at the scientific School of his master Albert the Great (ca. 1200-1280). For the Dominican genius, the unity of knowledge is less a theoretical process and more a “spirit” that guides his study and his work. His unwavering certainty of the uniqueness of truth, as well as his strong belief in the compatibility of the unique goodness and truth of God with all that good and true that was said by everyone in every epoch, made it possible for him to admit the Aristotelian corpus —among which there were not only philosophical titles, but also Meteorology, Astronomy, Biology, Physics— in the Commentaries and in the Quaestiones discussed at the university. With courage and balance he recognized the accuracy and depth of the knowledge gathered by Aristotle. At the same time, he was never afraid to point out, not only the distance between the Greek philosopher and Christian thought (where it was the case), but also the limits or even the contradictions that were present in Aristotle’s writings. After so many centuries, it seems difficult to imagine the innovative, and in some way, revolutionary, undertaking of such a search for a synthesis between religious and secular knowledge, the importance of which can never be overestimated. This courageous cultural work could be repeated today, John Paul II has said, only if knowledge from the natural sciences becomes available to theologians and it is properly used in their work. “Contemporary developments in science challenge theology far more deeply than did the introduction of Aristotle into Western Europe in the 13th century. Yet these developments also offer to theology a potentially important resource. Just as Aristotelian philosophy, through the ministry of such great scholars as St Thomas Aquinas, ultimately came to shape some of the most profound expressions of theological doctrine, so can we not hope that the sciences of today, along with all forms of human knowing, may invigorate and inform those parts of the theological enterprise that bear on the relation of nature, humanity and God?” (John Paul II, Letter to the Director of the Vatican Observatory, June 1, 1988, in Papal Addresses, p. 299).

The importance of Aquinas’ work also applies to the question of the Latin Averrorism and to the so-called “doctrine of the double truth,” whose historical and contextual formulation merits here some additional information. According to the Muslim philosopher Averroes (1126-1198), to whom the doctrine of the double truth is sometimes wrongly attributed, there is, instead, only one truth, that developed in the rigorous reasoning of philosophy. However, religious thought does not need to refer to such a truth because its way of talking about God, different from that of philosophy, need not rely on necessary causal relationships. According to Averroes, religion did not need any philosophical truths, given that its purpose was only to incite the feeling of the people having its source in the Koran. The Latin Averroists welcomed Averroes, but above all they welcomed his Aristotelian Commentaries, trying to read them in a Christian context. They did not support explicitly the doctrine “of the double truth,” but were not able to avoid its consequences. In fact, the Latin Averroists admitted that philosophy might reach, through rational demonstrations, conclusions different from those offered by the Sacred Scriptures. These conclusions would be formally correct but “untrue,” because “the truth” was only that which was transmitted by the biblical Revelation. It was precisely against this perspective that Thomas Aquinas strongly reacted. In all his works, he strongly endorsed the position that philosophical rationality, when correctly applied, was a way of reaching and knowing the truth. For him, philosophy, including Aristotelian philosophy, could be used as a rational instrument of theological thought. Philosophical conclusions, when rightly formulated, could by no means lead to contradictions to faith because of the uniqueness of truth. At the same time, Aquinas emphasized that the “reasons” of theology were not exhausted by those of philosophy. In fact, to talk about God requires the richest possible language, and, at times, philosophical language is not sufficient. For this last reason, he entertained the idea that, differently form Aristotelians, when talking about the first Principle and about God Platonic philosophers did so in a way that was more consistent with Christian faith, because of the transcendent perspective they assumed. On the contrary, they could not discuss the material entities in a satisfactory manner, because they placed the ultimate reasons of their knowledge and truth in abstract principles and separate ideas, in contrast to Aristotelians, whose language was more adequate to speak of material things (see In de Divini nominibus expositio, Proemio, II).

3. Projects of Unification in the Modern Age. In the Modern Age, the intellectual synthesis brought about by the Middle Ages appears no longer possible, for at least two reasons. The first is the on-going methodological diversification of all fields of research. The growing depth and expansion of the knowledge, first at the cosmological level, and later at the anthropological and biological levels, challenged the old project of “bringing all things back into unity”, as proposed by the theological view of the Middle Ages. As a result, the dialogue between the various branches of knowledge becomes more difficult, eventually causing the beginning of a gradual hiatus between scientific and humanistic disciplines, between the sciences of Nature and the sciences of the Spirit. The premises of this split were laid in the 17th century but its full development became evident towards the end of the 18th century and the beginning of the 19th century. The second reason is related to the possibility of carrying out a “scientific and autonomous reading” of the world, of human social and moral life, one that could set aside, for the first time, the teachings that Sacred Scriptures had offered on those same realities, although through the mediation of its interpreters. Now, not only could the motion of the heavens be explained by the laws of mechanics (Newton, Laplace), but even the study of the virtues of the government (Machiavelli), the rules of social life (Hobbes, Montesquieu, Shaftesbury), and the knowledge necessary for guiding the real progress of humankind (Comte, Marx), could now be deduced from sources other than Christian biblical doctrine. These matters had to be established autonomously, accepting for the first time the logic that the end was able to unconditionally justify the means. Although the philosophical movements of the Modern Age made use of concepts and categories of Christian origin, what now remained was nothing but its outer shell, its original meaning having been replaced by different contents (cf. Guardini, 1951). It is quite typical to represent this “emancipation” by a series of progressive steps of increasing severity. After removing the earth from the center of the cosmos (Copernicus), mankind would later also be “deprived” of the privileged condition previously occupied within the hierarchy of the animal realm (Darwin). Later on, human beings would lose even the possession of their own psyche (Freud). Finally, the discovery of boundless space-time dimensions in which Homo sapiens must now interpret and read his biological, geological, and cosmic history would contribute to upsetting our previous orientation, thus confining human nature to a quite marginal role.

These are very critical “changes,” all important to understanding how a certain unity of knowledge was lost, and what needs to be done to eventually put the pieces together again. Nevertheless, in order to not overestimate the real import of these changes themselves, some further questions should be addressed as well: Was the human being, and not rather God, what the Patristic-Medieval synthesis between the religious and secular readings of nature put at the center of the world? Did this supposed anthropocentrism concern the human being as such or, rather, the humanity of the incarnated Logos, Jesus Christ? Did we lose the unity of knowledge when the various disciplines began to use their autonomous methodological procedures or, rather, when the knowing subject began to abandon holding together a culture of the aims and a culture of means, that is, breaking the harmonious relationship between the moral view which supplied the grounds of human behavior and the pragmatic view that now suggested the praxis to achieve the required goals? Moreover, in order to better understand this split, we cannot ignore the role played by precise theories that introduced analogous radical separations, especially in Western thought: between faith and reason (Luther), between res cogitans and res extensa (Descartes), between pure reason and practical reason (Kant).

It is worth noting that in spite of the loss of the previous synthesis, the Modern Age did not renounce manifesting its own tendency towards unity. In fact, such a tendency and its power of cohesion implicitly gave rise to a number “philosophical systems.” Modern philosophy attempts unification rationalistically, first with Descartes and then with Kant. It also does so idealistically, by entrusting to the Spirit, to Reason, or to History the task of unveiling the role of the parts within the whole. Knowledge is “one” because spirit, reason or history are one. Approaching our own times, a certain way of understanding techno-scientific knowledge inherits, at the beginning of the 20th century, such a philosophical process, particularly through Neo-Positivism, especially in its physicalist and more radical versions. Although it has been criticized by scientific thought itself, which pointed out the intrinsic incompleteness and the inescapable outcome of skepticism brought about by this reductionistic program, neo-postivistic illusion still seems to survive within the scientism channeled by the media and unconsciously accepted by a large part of public opinion.

From the beginning of the 17th century, the search for some unity of thought prompted the creation of comprehensive proposals: the Dictionary Historical and Critical (1695-1702) by Bayle, the Enciclopédie (1751-1772) by Diderot and d’Alembert, the Encyclopedia of Philosophical Sciences (1817) by Hegel, up to the International Encyclopedia of Unified Science by Neurath, Carnap and Dewey. Because of World War II, and also, to a greater extent, because of the breakdown of the epistemological current of thought supporting it, of this last work they were able to publish only the first volume, in 1938. Among these examples, we could also include the contemporary Britannic Encyclopedia (which first appeared in 1768), a project whose pragmatic philosophical character easily comes into view by reading some key-entries (such as, for instance, “truth”). ”). Among the projects started in Catholicism, it should be mentioned also the theoretical design of a unity of all the sciences as outlined in the impressive Theosophy (1846-55) written by Antonio Rosmini, and later developed in other works of his, which represents the most ambitious project of that epoch. In the Modern Age were not always encyclopedias, but often smaller and very influential works, which suggested strong new lines of thought towards some unification of knowledge. Outstanding examples are A Discourse on Method (1636) by Descartes, the Principles of Natural Philosophy and Religion (1714) by Leibniz, the well-known Kantian Critiques (1781-1790), the Phenomenology of Spirit (1807) by Hegel, the Action (1893) by Blondel, the Principia mathematica (1910) by Russell and Whitehead, and the Tractatus logico-philosophicus (1921) by Wittgenstein. In the socio-political field we find other important attempts at a unified interpretation of reality, as were the Communist Manifesto (1848) by Marx and Engels, and the Protestant Ethic and the Spirit of Capitalism (1904) by Weber.

Contemporary times have been witness to the wide-range project put forward by hermeneutics. This philosophical current has certainly contributed to a better methodology of knowledge, by researching the criteria that should be employed when interpreting a written text. These criteria must take into consideration not only an object (the text), but should also include the position taken by the subject in the “world made up of this same knowledge.” In this regard, once again works such as Introduction to the Science of Spirit (1883) by Dilthey, Being and Time (1968) by Heidegger, Truth and Method (1960) by Gadamer, The Conflict of the Interpretation (1969) by Ricoeur, Of Grammatology (1967) by Derrida, and many others, intend to provide an answer to a unifying project. Currents of thought such as structuralism, behaviorism, the psychoanalytical movement or the philosophy of language, can be also considered a unifying reading of reality, of knowledge and of behavior. Contrary to other methodological unifications mentioned above, these last do not seem to be interested in the unity of knowledge as such. In a certain sense, hermeneutics itself and the currents it originated are concerned with unification insofar as their investigation are aimed at the reconstructing the possible unity of a meaning. In so doing, the risk exists of ending by confining itself into a closed, endless circle, having no longer interest in the universality of truth, thus frustrating the effort to understand and interpret.

Generally speaking, the projects of unification of the Modern Age, including also part of contemporary times, appear in the form of “philosophical systems.” Often inspired by the proposal of a single author, it is easy to find in their structure a sort of “vision” of the world, of reality or of mankind, that is mediated, explained and diffused through categories and pre-understandings of subjective nature, usually at work within a somewhat idealist perspective. In the previous paragraphs I have purposely omitted talking about phenomenology and metaphysics just because, among many other methodological proposals, these two philosophical perspectives have the explicit task of keeping track of reality and of being regulated by what reality reveals, suggests or even imposes on the consideration of the subject. Neither phenomenology nor metaphysics come about as “systems,” and cannot be traced back to a single thinker. This is especially true of metaphysics, which expresses a “capability” and a “method” of thinking, that, under a variety of labels, intersects any philosophy looking for Truth, Beauty and Good. Both metaphysics and phenomenology represent a modality of linking together the knowledge reached by our senses, and that which transcends them, a capacity of going up and down in a circle, from effect to cause and from cause to effect, making possible their complementary and integrated application.

III. Interdisciplinarity and Dialogue between Different Fields of Human Culture: does a University Campus still exist?

Before examining how to build unity around the object and the subject of knowing, it is worthwhile to remember that there is a “place” where the dialogue between various disciplines has historically occurred, a place whose building and logic are precisely those of justifying the presence of different branches of knowledge all together in the same Institution. The University has been such a place. In the genetic code of universities there has been, from the very beginning, the idea that the various Departments should have a certain “intellectual communion.” Since the Middle Ages and the Renaissance, up to the appearance of modern universities according to the model conceived by Wilhelm von Humboldt for the University of Berlin (1810), an interdisciplinary approach and a tendency towards the unity of knowledge remain the most distinctive characteristics of universities. For this reason, the various “ideas of university” described by different writers merit some attention (see for a synthesis Rigobello et al., 1977; Tanzella-Nitti, 1998). Among these “ideas,” we have those described between the 18th and the 19th centuries by J.G. Fichte (Ideen für der innere Organisation der Universität Erlangen, 1806), W. von Humboldt (Theorie der Bildung des Menschen, 1793; Antrag auf der Errichtung der Universität Berlin, 1809), and the exhaustive account of the importance of university training provided by J.H. Newman (The Idea of a University, 1852). In the 20th century we have, among the others, the works by Jaspers (Die Idee der Universität, 1923 and 1946), Ortega y Gasset (La misión de la universidad, 1930), and Guardini (Die Verantwortung der Universität, 1954). All of these authors have stressed, in one way or another, the “contextual” character of university studies, their belonging to a common picture, and to a unitary intention, even if the models suggested to build up such unity have been quite different according to the personal perspective of each author. In spite of their differences, they all agree on one basic idea: the university campus is understood as being a place where people do not meet by chance; instead it is a place defined more by an intellectual architecture than by a logistic, urban or functional plan.

Concerning the need for a contextual and interdisciplinary research of truth, Karl Jaspers wrote the following: “Propelled as it is by our primary thirst for knowledge, this search is guided by our vision of the oneness of reality. We strive to know particular data, not in and for themselves, but as the only way of getting at that oneness. Without reference to the whole of being science loses its meaning. With it, on the other hand, even the most specialized branches of science are meaningful and alive. [...] Thus, what determines the actual direction of any inquiry is our ability to perpetuate, yet continuously to interrelate two elements of thought. One is our will to know the infinite variety and multitude of reality which forever eludes us. The other is our actual experience of the unity underlying this plurality.” (The idea of University, London 1965, p. 38). Similar reflections had been suggested one century before by Newman: “In saying that Law or Medicine is not the end of a University course, I do not mean to imply that the University does not teach Law or Medicine. What indeed can it teach at all, if it does not teach something particular? It teaches all knowledge by teaching all branches of knowledge, and in no other way. I do but say that there will be this distinction as regards a Professor of Law, or of Medicine, or of Geology, or of Political Economy, in a University and out of it, that out of a University he is in danger of being absorbed and narrowed by his pursuit, and of giving Lectures which are the Lectures of nothing more than a lawyer, physician, geologist, or political economist; whereas in a University he will just know where he and his science stand, he has come to it, as it were, from a height, he has taken a survey of all knowledge, he is kept from extravagance by the very rivalry of other studies, he has gained from them a special illumination and openness of mind and freedom and self-possession, and he treats his own in consequence with a philosophy and a resource, which belong not to the study itself, but to his liberal education.” (The Idea of a University, Chicago 1987, pp. 186-187).

To Newman’s and Jaspers’ citations we could add those of a third author, John Paul II, who also served as a university professor for more than 20 years. On the occasion of his speech to university professors in Turin, Italy, in 1988, he said: “Now, it is precisely characteristic of the university, which is by antonomasia universitas studiorum as distinct from other centers of study and research, to cultivate a universal knowledge in the sense that in it every branch of knowledge must be cultivated in a spirit of universality, that is, with the awareness that each one, although diverse, is so linked to all the others that it is not possible to teach it outside the context, at least intentional, of all the others. To withdraw into oneself is to condemn oneself, sooner or later, to sterility and to risk exchanging the norm of total truth for a keener method of analysing and grasping a particular section of reality. The university, therefore, must become a place for meeting and spiritual comparison in humility and courage, where people who love to learn can learn to respect, consult, and communicate with one another, in an interweaving of open and contemporary knowledge with the goal of leading the student towards the unity of the knowable, that is, towards the truth which is sought and safeguarded beyond any manipulation» (Discourse to the Students and the Faculty Members of the University of Turin, Turin, September 3, 1988, n. 3, ORWE, October 10, 1988, p. 3).

Working in a discipline “within the context of the others” or “within the logic of a campus.” as pointed out by these authors, does not mean being “a know-it-all,” but rather an educated person, who is not satisfied with the simple methodological analysis of “parts” of knowledge, because he or she is convinced of the fact that truth and meaning find their place in the “whole.” From the opening up of new horizons caused by applying the interdisciplinary perspective, not only does the study of each individual discipline gain an advantage, but so does, and even more so, the service that can be offered to human and scientific progress. In order for the university to become a “place of unity of knowledge,” the rationality taught there must concern not only the realm of means (know-how), but also the realm of ends (know-why), that is, it must involve not only science, but also wisdom. In other words, universities must have, at the center of their reflection, the fundamental questions about Truth and Good, about the meaning of life, about the place of the human being in the universe, and about the personal and social responsibility that is associated with any knowledge. Excluding these questions from the university would mean interrupting its ages-long tradition, thus enervating its nature and mission. This is of extreme importance today. Today, opposed to what happened in the Middle Ages, the field in which the great traditions of thought meet and confront each other is no longer the scientific arena of the universities (cf. MacIntyre, 1990). The debate has now moved away from the campus to the area of public opinion, to the logic that creates and controls the consensus, often driven by political, ideological or financial motivations. Such a shift of arena brings about obvious dangers. There are, today, planetary problems that for their content and size involve the future of mankind. These problems, that concern economy, techno-science, ethics, and law, bring about conflicts and clashing of interests precisely because one place is lacking —the university— where knowledge, results, and procedures can be critically evaluated without any economic, social or political conditioning, that is, super partes, thanks to the maturity of a well-prepared education, able to apply the humanistic resources of science and to train technicians aware of the needs of a more human society.

IV. The Search for Unity in Reflecting upon the Object: Beyond the Interdisciplinary Approach

Any reflection on the unity of knowledge should begin by considering the unity of theknownobject (see above, II.1). In fact, any subject portrays, with many efforts and not without mistakes, what is found in the reality of things. The unity of knowledge speaks of, and whenever possible it describes and gives reasons for, the unity of objective reality. Only when the unity of the object is not overlooked, the activity of the knowing subject can be thought in a non-subjective way. In this case, it also becomes possible to look at the truth expressed by the action (phenomenology) without neglecting the truth revealed by the being (metaphysics). Moreover, a unification of the object also allows the inclusion of a theological perspective, given that Revelation shows, in a radical and basic way, that nature is “one” because of the uniqueness of its Creator, and that the history of the world is “one” because it receives meaning from He who is the beginning and the transcending end of the whole of history.

Contemporary science willingly speaks of the unification of the whole of physical reality, especially in the context of theoretical physics. There is a general agreement among scientists that if science can speak and work in these terms it is because “nature can undergo unification.” (cf. Salam, 1990). Historically speaking, theoretical unifying formalisms (gravitational theory, electromagnetism, the unified fields theory, quantum electrodynamics, electro-weak unification, etc.) have almost always preceded their corresponding experimental results. It is also true that these results, that is, their objective counterpart, have rightly motivated the efforts to come. In terms of theoretical involvement and of economical resources (as shown by the name Big Science), the costs of such an enterprise have quickly gone up every time a new step has been undertaken. From a dynamic perspective, a strongly unifying picture has resulted from both contemporary cosmology and biology. The laws governing the structure and dynamics of the universe are able to link, in a consistent and harmonious way, microphysics and macrophysics. Also the development and diversification of living organisms, and of the biological processes driving their phenomenology, show a great underlying unity, going from the molecular level (the structure of DNA) to much more complex functions. The presence of the human being, whose historical emergence would seem to interrupt, at least because of its uniqueness and self-awareness, this progressive and integrated phenomenology, in reality it reveals a new and greater level of unification. In fact, in order for mankind to exist, all the universe must also exist and must be one: as shown by most of the philosophical reflections on the Anthropic principle, in our universe there is nothing unnecessary or meaningless. However, the final step of conceiving of the whole of universe as a single object, strictly speaking, transcends the methods of empirical science. The object of all that exists, the problem of the All, is a philosophical problem, not a scientific one, despite of the relatively diffused approach to a “theory of everything” we find today in theoretical physics.

The recent attention paid again of the idea of “form” (in its Aristotelian conception or in other ones associated with it) in the study of many phenomena, particularly in chemistry, biochemistry and biology, seems also to have accredited greater importance to the unity of the object. There are properties that seem to be grasped and recognized only by abstracting from the parts and focusing on the whole. We also find “morphogenetic” categories which seem to govern the formation and the reproduction of some recurring patterns. This regards both the structural aspects of physical or biological entities and, especially, their dynamics. It is under a lively discussion whether the use of “goal-setting” principles, or even the simpler idea of coordinated functions, could help the understanding of phenomena and processes in the realm of biochemistry and biology. The rediscovery and the successful application of analogy in science shows once more that we are facing a reality that includes some unifying criteria, while at the same time maintaining different levels of complexity. Researchers have become aware of the need for an open science, structured on levels that are organically connected by analogy, as the limits of reductionism and of a self-reliant knowledge have become more evident.

Thus, various disciplines are encouraged to work closely together. A more consistent study of what once they thought to be their own separate object, now requires the contribution of other fields of knowledge. One can be certainly tempted (as frequently happens) to expand the methodology proper to a specific field into another contiguous field of knowledge, but this clashes, sooner or later, with the impossibility of working in the new field having the same degree of decisional power and the same logical completeness one had within the original field of study. Then, the need for new methodologies becomes more evident and new disciplines spring up, so emphasizing a re-evaluation of an interdisciplinary approach. And it happens that in an era of specialization and fragmentation of knowledge such as ours, a field of study which has the courage of opening itself to dialogue with other fields —thus accepting the challenge coming from other sources of knowledge— is surprisingly helped to better understand its own object. Originating from a need inherent to scientific endeavor itself, the interdisciplinary approach represents today an interesting innovation, one in open contrast with the positivistic and neo-positivistic methodological reductionism, that dominated till the rising of the “new epistemologies.”

Taken in its “weak” form, which is normally the ordinary way people speak of it (see above, I.1), the interdisciplinary approach has, however, two limitations. The first is that interdisciplinarity can be driven by a purely pragmatic functionalism. This happens when the request for an integration of different branches of knowledge only comes from a strong desire for a higher level of efficiency and production, not from the will to answer scientific, or even existential questions, having a particular foundational value. The second limitation is the risk of a certain ingenuosness, as when the interdisciplinary approach is understood as a simple “accumulation” of experts or of know-how, creating the illusion that gathering scientists, economists, lawyers, philosophers, and even a few theologians, around the same table, it is enough to solve mankind’s greatest problems. In order to get to a deeper process of unifying knowledge, the interdisciplinary approach must have access to a philosophical consideration of nature (philosophy of nature) and of knowledge itself (gnoseology).

To achieve this, the interdisciplinary approach must evolve from a simple methodological strategy into a progressive opening up to different levels of the understanding of reality. This is the only condition capable of triggering a “strong” interdisciplinary dialogue, following a path which looks for both a synthesis and a foundation. Only under these conditions does it become a “trans-disciplinary” and “meta-disciplinary” dialogue, paving the way for a twofold itinerary that lets a specific discipline cross both its external and its internal boundaries: going outward, by searching for a meta-language and a meta-science allowing the successful handling of what internally was not clear enough, or could not be put properly into context; and going ever inward, by searching for a foundation to those methods and principles whose ultimate reasons do not belong to the field of knowledge that employs them. In this way, the effort for performing more profound analyses no longer ends in mere de-composition, but opens up to the search for a foundation.

Philosophy of nature and metaphysics play an important role in any gnoseological itinerary as the one depicted above. On the one hand, having its character of “first philosophy,” metaphysics offers some intuitions and principles that make any science possible. Yet the truthfulness of these insights, formally impossible to prove, is based on an immediate knowledge of realistic kind, and on common sense (in its philosophical meaning). On the other hand, representing a philosophy of being capable of going beyond sensory knowledge, metaphysics makes it possible to reach higher levels of comprehension and also of more general causation which give reason to what has been discovered and analyzed by each separate science. Hence, metaphysics can be seen not only at the foundation of other disciplines but also as the higher level of knowledge to which they all tend. The well-known Cartesian image, which presents metaphysics as the roots of a tree whose trunk is represented by physics and mathematics and whose fruit is represented by more elaborate sciences, appears to be incomplete and somewhat misleading. Of knowledge, metaphysics concerns the roots as well as the fruits. Metaphysics does not deal with the justification knowledge because it simply “supports it from the bottom,” but also because it manifests its highest objectives. Getting to know these objectives from high above grants unity to the knowledge of the entire tree because the goal is to unveil more general causes, including the possibility of ascending to the existence of one first Cause.

Other visions compatible with the one I have illustrated can be found in a number of authors who have maintained a close dialogue with the natural sciences. It is worth mentioning the synthesis proposed, in our own time, by J. Maritain (1882-1973) and by M. Polanyi (1891-1976). The first has developed a philosophy of nature inspired by the known distinction of the “three levels of abstraction” (physics, mathematics, and metaphysics) and by the complementary relationship between empirical and ontological analyses. This approach also manages to explain, as shown in an extremely important study titled Distinguish to unite. The degrees of knowledge (1932), how a learned and a mystical knowledge would observe at the same natural objects analyzed by sensible, scientific knowledge. The same “material object” (nature), as suggested by the classical Aristotelian vision, can thus be perceived through different “formal objects” (wisdom, philosophy, science). Polanyi has suggested a hierarchic theory of knowledge consisting in various levels of a progressive understanding of reality. According to his approach, each level functions as if it were an “open system.” Within each system, logical and ontological boundary conditions are regulated by the higher level. The levels of (logical) comprehension coordinating the various sciences correspond to the way in which nature is structured following a given (ontological) hierarchy. Here, the highest and widest levels cannot be reduced to the inferior levels, nor fully described employing the terminology proper to these latter (cf. Personal Knowledge, 1958, in particular part IV). The intelligibility of reality is structured in the same manner: because of the “opening up” of each system, structures and processes found in the lower levels are understood in the light of those belonging to the higher levels. Polanyi’s synthesis was later expanded by T.F. Torrance (1913-2007) to include theology also (cf. Transformation and Convergence in the Frame of Knowledge, 1984).

Among the most recent philosophical reflections on interdisciplinarity and metadisciplinarity we find the contribution of E. Morin (1921- ). Coming from the field of the sociology and philosophy of mass communication, the French thinker has tried to determine which methodology to adopt in order to better study the problem of complexity. Starting from the material world, in which complexity is seen as a constant and, in part, also the most fundamental, modality, with which nature offers itself to our study (cf. La Méthode, 1977-1991), Morin includes in his studies the complexity of the living organism (La vie de la vie, 1980) and of human knowledge (La connaissance de la connaissance, 1986). The follower of a philosophy deriving its categories from the behavior of nature and of a science increasingly aware of the interaction between subject-object, Morin has emphasized the need to elaborate a way of thinking that goes beyond the dualistic dialectic approach of Western thought. His approach intends to include the idea of a unitary logic, according to which human thought would be part of a habitat made of more than just an intellectual dimension, being our thought also influenced by biology, geology and ecology. Morin has made long strides towards a methodological innovation aimed at unifying the sciences, as shown by the Charter of Transdisciplinarity, whose articles Morin signed together with Lima de Freitas and Basarab Nicolescu (cf. Nicolescu, 2002). However, his methodological intention seems to be confined to the field of a purely cognitive strategy and to be exclusively concerned with the identification of the ever-changing and adaptive laws of the ecosystem —including consciousness— thus betraying his lack of interest in a philosophy capable of giving some transcendent foundation to science and to human conscience.

New attempts for a unity of knowledge to be built on an interdisciplinary-dialogic approach have been developed by several English-language authors interested in the topic of the science-theology dialogue. In general, these models are mainly “models of dialogue or comparison” (I. Barbour, A. Peacocke, R. Russell), rather than real unification proposals. N. Murphy and G. Ellis (1996) have suggested a project of unity of knowledge on hierarchic levels. This structure would be ideally represented by a double “Y.” One Y vertically opposite the other. Its axis, represented by the progressive complexity of physics, chemistry, biology, splits into a fork where on one side we find those sciences that deal with global systems and on the other side those disciplines that instead study details, particularly those disciplines related to the human sciences. Both branches, the one controlling physical and natural behavior on a wider range and the other which develops through anthropology and ethical issues, are again unified at the top, in a way of knowing that includes wisdom and the theological dimensions, a way of knowing which, in turn, is called upon to provide reasons for both the lower branches.

V. The Building of Unity inside the Subject: the Unity of Knowledge as Listening to, as Habitus and as Act of the Person

In the beginning of this article I mentioned the importance of not losing track of the role of the subject who makes science, thus re-evaluating the intentional, personal, aesthetic, and moral nuances associated with each knowledge activity (see above, I.1). All epistemological paths lead sooner or later to the anthropological field, a field where all questions about what is the world and what can be said about the world necessarily lead to a new, bigger question: Who is the subject who knows? What does the human being mean in the being of the cosmos? Ignoring the anthropological value and the personal dimension of scientific knowledge for the sake of the objectivity of science or for the end of ensuring an objective and impersonal communication protocol, would result in depriving science itself of its meaning. In fact, human beings represent both the presupposition and the final goal of all scientific knowledge.

The discussion of the unity of knowledge cannot be limited to a simple reflection on the articulation that each discipline should have in a research project or in a program of university training. Instead, it must be founded on a deeper basis. It must be capable of involving not only “the sciences,” but also “the person who makes science.” The unity of knowledge does not result from the unity of method or from the unification of different contents. Instead, it results from interiore homine, that is, from inside the person. This approach draws upon a popular expression of St. Augustine: “Noli foras ire; in te ipsum redi; in interiore homine habitat veritas — Do not desire to go outside, return in yourself,  the truth dwells inside your consciousness.” (De vera religione 39, 72). Below I will try to describe three possible progressive levels of such a program: the unity of knowledge as “listening to,” as habitus (habit), and as “act of the person.”

Passing from the gneosological to the anthropological realm, the unity of knowledge no longer appears as a “vision of the world.” Instead, it appears as “the listening to the world.” Based on such a perspective, the dialogue/comparison between the different branches of knowledge permits the overcoming of the impasse of ideologies, which often present themselves as Weltanschauung (world-view), and usually refuse to open up to the realism of knowledge voiced by things. Unity comes from listening to nature, and listening to the other (by now with a small “o”). To accept this, we must endorse the constructive, and not totally revolutionary, character of any human knowledge. We must accept the humility of verifying and comparing. We must admit the incompleteness of one single method compared to the display of all the different levels of complexity and to the unpredictability of reality. Among the sources of knowledge which invite to “listen to,” there are certainly: “tradition” (all the knowledge and contexts historically acquired by a community); “human faith” (trust in the knowledge owned by others and in the experience they made, a trust necessary to the development of all knowledge); and “scientific faith” (belief in the objectivity, rationality and intelligibility of the physical world). A way of knowing based on “listening to” still remains a rigorously critical knowledge, but one in contrast with knowledge based on doubt or suspicion.

To a unification program built on listening, theology contributes with its specificity, emphasizing that Revelation is a knowledge derived precisely from listening. It is the listening to the Word of God Who speaks through His created beings and Who reveals Himself throughout history. Giving priority to listening (whose meaning transcends the mere physiological experience of hearing) does not mean ignoring the fact that an “intellectual, comprehensive look at the world” can also unveil important connections which lead to unity. Instead, it means emphasizing that it is in the listening to a word, more than in the watching, that the subject understands him– or herself as a partner of “someone else,” as the receiver of a gift, as a person who demands completion, precisely as an “I” facing a “you”. Acknowledging the existence of such dynamics of reciprocity and completion, one intrinsic to our own existence, represents the first step in the search for unity. It also represents the best warranty against Descartes’ approach of self-sufficiency, which tried to build all knowledge on the knowledge of the self. “Listening to” represents, in the end, the confession that the subject is not the whole, that we arrive at self-knowledge through something else that we have not yet, through a word, ultimately God’s Word, by which we are interpreted and decoded, through an encounter with the Other (now with a capital “O”). Once heard, the word generates in the listener the possibility of a new “glimpse,” that is, a coming back to objective reality, in which we now recognize, surprised, a meaning that before had been concealed. Hence, the subject no longer bears the task of having to build up, alone, a “vision” to embrace plurality. Instead, he or she is guided to “look at” the world following the clues of He who knows and possesses the ultimate meaning of the world.

From a theological point of view, the question arises whether the primacy that a Word heard has for gaining knowledge, particularly explicit in the Old Testament, could be in contrast with the importance given by the New Testament to the act of “looking at” compared with the act of “hearing,” also remembering that the God of Israel could only be heard and not seen (cf. 1Sam 3:10; Is 55:10-11; Ex 33:18-23; see also Jn 1:18). However, the contrast is only apparent. In the New Testament context, the importance of “seeing” depends on the major role played by the visibility of the Incarnated Logos, the Word made flesh (cf. for instance Jn 1:14; 1:39; 20:8; Lk 24:39; 1Jn 1:1). The correspondence between "to see" and "to know," especially clear in the writings by St. John, never takes the character of a “vision” (intended as Weltanschauung, in its original idealistic meaning). The appeal to us to see allows the guiding of the subject towards the definite objectivity and the historical truthfulness of the humanity of the Logos, Jesus Christ. It appears very much in tune with a gnoseological realism, capable of orienting the way in which the subject has to face the world and interpret it in the light of God’s words, far from any risk of idealism.

After the “listening to,” the second step towards the unity of knowledge is to recognize that unity is not a sum of many parts of knowledge, but instead a habitus. It isthe “virtuous habit,” already trained by listening, that leads the subject to integrate his or her own professional area into the intentional context of all the others. As a result of such a habitus —in the end representing the training of an educated person— we can face new situations and emergencies with a kind of “creativity”, notwithstanding the limited knowledge of our specific discipline. This attitude well bears witness of the unavoidable transcending aspect of culture upon nature. In addition to avoiding the risk of reductionism, to understand knowledge as a habit allows the subject to experiment the “immanent dimension” of culture (i.e. the fruits of culture which are intrinsic to the person), and to develop the authentically “human” dimension of the scientific enterprise. In this way, it also becomes easier to understand the meaning that one’s study has for the total good of the person. The unity of knowledge as habitus does not depend on the ever more extensive augmenting of the knowledge one has already acquired, but rather on the understanding of the value that this knowledge has for one’s own life, for society and for the progress of humankind. In this way we create the conditions to overcome that inner fragmentation which breaks down the person, shattering in many incommensurable pieces our experience of living, whose multiplicity and independence make it difficult to gain a deeper truth. In order to achieve some unification of knowledge, first of all we must understand who the person is in whom such knowledge must be unified.

There is a meaningful convergence between the unity of knowledge as habitus and what we could call “the spirit of a university scholar.” The latter relies on the ability of critical reflection and listening, intellectual rigor, a honest will to collaborate, an opening up towards a constructive exchange of knowledge, sensitivity towards humankind and its integral promotion. The “knowing of not knowing,” characterizing those who strongly experience a multidisciplinary context, never impinges on the desire of knowing; instead, it represents a stimulus to dialogue and to putting into relation ourselves and others, in a search for intellectual maturity. Due to the experience of their own university studies, those who have developed such a habitus can find, sooner than people who do not share this same habit, the solution to particularly complex problems, especially those problems which demand a universal context and a logic closer to the common good. Those who are accustomed to work with a “university habit” can undertake better than others the task of building up a culture of solidarity. Common good and solidarity can today be carried out more efficiently only if based on a planetary context, that is, precisely the typical context of any research carried out at the academic level, open to a living international confrontation with every research group and every scientific outcome.

The last step is to understand the unity of knowledge as “act of the person.” Supported by an intellectual habitus that is capable of assigning the meaning of each part within the logic of the whole, and remains open to listening to the other, the search for unity can be organized and consolidated around the action of the subject. It is the action that the subject performs when compelled by the totality of knowledge that he or she has judged meaningful and reasonable; an action, therefore, that reveals his or her most intimate intentions. It is the intellectual act of a cultivated person —whom J.H. Newman would have called a gentleman— someone who has not neglected, because of poor intellectual honesty or prejudice, any important contribution in the making up of his or her judgments, and in making his or her life choices. However, any virtuous habit is not an end in itself and the search for unity needs here a further step. Habit is oriented to praxis, to taking the responsibility coming from one’s knowledge. This responsibility can go as far as asking questions about what makes a society a “civil” society, what makes a family “human,” what qualifies a science as “true.” When I say that habit or virtue are not an end in themselves, but are aimed at action, I do not intend to deny that the development of a habit of life is obviously preceded by the corresponding acts (to which a temporal priority would apply). Instead, I simply want to underline the natural orientation of all habitus towards an activity possessing a higher intensity and a greater synthetic value. It is what happens, for instance, about the virtue of prudence, which is a virtue that prompts towards an intelligent and wise behaving, not to passivity or inertia.

What is the “nature” of the act, one might wonder, that grants unity to the intellectual experience of the subject once he or she agrees to ask the “last questions” about the origin of the whole, the sense of life, the place of human beings in the universe, the ultimate cause of human dignity and what grants authenticity to human progress? I am convinced that such an act has a “religious” nature. By this I mean the personal commitment to look for truth, and the moral consequence of embracing truth once it has been found (cf. Dignitatis humanae, 2). In a certain way this is a consequence of the fact that all the previous questions are, at the same time, philosophical and religious. This would mean that, in the end, as declared on one occasion by John Paul II, “we move towards unity as we move towards meaning in our lives.” (Letter to the Director of the Vatican Observatory, June 1, 1988, in Papal Addresses, p. 297). Culture can thus become a path towards the Absolute. Only when the subject wants to move towards the Absolute and the ultimate meaning of everything, does he or she find the motivation to draw together the various aspects of knowing into a synthesis, which can give an answer to truly relevant questions, those more existentially challenging. Hence, unity of knowledge does not depend on the “quantity” or on the “type” of knowledge we have. Instead, it depends on the “way” in which we can relate this knowing to the reasons of our life. A way of knowing which “can be unified” is, in the end, a way of knowing that remains open, not only to the issue of truth, but also to the quest for God.

A preconceived agnosticism or a radical nihilism, that intended to dismiss the problem of truth, are both poles apart from any possible discussion of unity of knowledge. Overcoming such an intellectual position is a necessary philosophical premise —not ideological but learned— in order to begin any discussion on this subject. We find a clear analysis of this in a page of Fides et ratio (1998): “One of the most significant aspects of our current situation, it should be noted, is the ‘crisis of meaning.’ Perspectives on life and the world, often of a scientific temper, have so proliferated that we face an increasing fragmentation of knowledge. This makes the search for meaning difficult and often fruitless. Indeed, still more dramatically, in this maelstrom of data and facts in which we live and which seem to comprise the very fabric of life, many people wonder whether it still makes sense to ask about meaning. The array of theories which vie to give an answer, and the different ways of viewing and of interpreting the world and human life, serve only to aggravate this radical doubt, which can easily lead to skepticism, indifference or to various forms of nihilism.” (n. 81). On the contrary, a philosophy capable of re-discovering its vocation to wisdom, to search for the ultimate meaning of life “will be not only the decisive critical factor which determines the foundations and limits of the different fields of scientific learning, but will also take its place as the ultimate framework of the unity of human knowledge and action, leading them to converge towards a final goal and meaning.” (ibidem).

This leads me to again mention the university as a possible “place” for such intellectual cooperation. If the philosophical and existential questions around which the knowledge of the subject is joined and unified are “universal” questions, then, by right, they also belong “to the university.” Moreover, these questions must be addressed inside a university. For this to happen, it would suffice that those who teach and work within the walls of a university had no fear to show their personal involvement in a search for unity and truth. A university professor who is open to the unity of knowledge is a professor capable of sharing with others a similar involvement. Such a professor is whom we usually name a “master,” that is, a “teacher” with capital T. A Teacher is someone who has been able to transmit to the students his or her personal unity of knowledge, a unity reached, at times, with great difficulty and hard work. We remember true “teachers” because, along with the subject-matter they taught, they were also able to communicate to us their love for what they were teaching. They also made it clear to us what role such knowledge had in their whole existence. By doing so, they opened up to us the way towards the “end,” without stopping at the “means.” More than the specificity of their teaching, we better remember their ability to listen, their intellectual habitus, the position they took in the face of deep existential questions, all things in which we students were invited to take part. In other words, a true teacher is aware that students cannot be impelled to know it all without teaching them first the meaning of what they are asked to learn. It is in the openness towards this search for meaning that the person can gradually get back that “inner center” that the progressive forgetting of the ultimate questions about the truth, about the dignity and the destiny of the human person —not the mere increase and diversification of the disciplines— had left beyond.

VI. The Unity of Knowledge and the Unity of the Mind of Believers

The trustful encounter with the word of God and the personal commitment to religious faith prompts the believer towards a new and even more ambitious project of unity of knowledge. This is nothing but the project of combining faith and reason in one’s personal knowledge, integrating them not as abstract entities, but as personal acts demanding unity, any fragmentation being perceived as a source of disease.

1. Faith and Reason in the Unity of the Person. The search for this new and higher level of unity generally begins by realizing that reason comes before faith and never abandons faith. Recalling the twofold mistakes pointed out by Blaise Pascal —admitting only reason or rejecting all reason (cf. Pensées, n. 3)— the believer knows that God is respectful of human nature and intelligence, and He created men and women capable of recognizing how reasonable a response to faith is. Hence, obedience to the faith does not lessen the value of reason, but simply goes beyond it.

The role of reason, paradigmatically summarized by the invitation to be “ready to give an explanation to anyone who asks you for a reason for your hope” (1Pt 3:15), has been present alongside the evangelization of the Greek-Roman culture during the early centuries of the Christian era. While condemning idolatry, polytheistic myths, and all pagan behavior not compatible with the Gospel’s message, Christians accepted the philosophical inheritance of that same culture, which had achieved important reflections on nature, human life, and the divine, cleansing it of errors and aberrations. In his speech in Athens, St. Paul refused to associate the name of God to any one of the gods of the pantheon. Yet, he did not neglect that the God he was announcing, was the same God creator of heaven and earth, the same God that many people worshipped without knowing Him and whose providence towards all created beings is always before everyone’s eyes (cf. Acts 17:22-31). The role of reason in the response of faith, often summarized as the Christian option in favor of lógos and against myths (a bit approximate according to the point of view of hermeneutics, but substantially correct according to the point of view of its religious content), was discussed at length by the Fathers of the Church. St. Augustine affirmed, in this respect, that “the authority [of the faith] is never abandoned by reason, because it is reason that decides whom we have to believe in.” (De vera religione, 24, 45: PL 34, 141). Maintaining a constant dialogue with philosophical thought, theology has greatly taken advantage of reason to counteract the charge of irrationality first raised against it by ancient materialism and later by modern atheism. Theology has also resorted to reason to understand which was the correspondence between the philosophical notion of God, as reached by the best philosophical speculation of the Ancient Age, and the image of God revealed by the Sacred Scriptures, specifically by Jesus Christ. In the search for this crucial connection, two positions have generally been avoided. On one side, it was rejected the idea that all the questions about God raised outside the biblical Revelation had to be judged irrelevant or meaningless; on the other hand, it was also denied a total identity between such two images of God, thus keeping one’s distance from concluding that faith is completely grounded in reason only.

The close correspondence between faith and reason, as part of believer’s unity of knowledge, goes beyond a mere “compatibility judgment,” that is, beyond the finding that the truths of faith do not contradict the conclusions of reason. Christian thinkers of the Ancient and Middle Ages were aware of a precise function that reason played “within faith.” To accept this role is not only the distinctive character of theology as such but also a necessary requirement for any truly Christian thinking. It is reason that leads one to understanding the coherence and the mutual implications of the great Christian mysteries, thus allowing theology to grow as intellectus fidei (the intellect of the faith), that is, as “the science of faith” in the real sense of the word. Thanks to the lumen fidei (the light of faith), reason can reach truths which, when reason is left alone, would remain out of its range. After grasping such knowledge, it reflects on it and penetrates it, fully understanding its articulation, beauty and consistency. Receiving the Revelation of God allows reason “to look at things with the eyes of faith,” and extends its gaze even further. Christian tradition has often expressed the logic of this unity-circularity between faith and reason resorting to St. Augustine’s words, who exhorted not only “to understand in order to believe” (intellige ut credas), but also “to believe in order to understand” (crede ut intelligas) (Sermones, 63, 7: PL 38, 353; cf. Fides et ratio, 16-35). Enriched by the Holy Spirit’s gifts of insight and science, the Christian faithful can look at the realities of the world in a filial spirit, that is, in harmony with the will of God-Father, judging everything according to the value it has in God’s plan; in this way, the believer reaches a higher understanding of creation, more profound than that granted by the learned of the earth (cf. Ps 119,99-100).

It becomes obvious that at the center of such “circularity” there can only be the person, that is, the believer. It is not reason which brings connections and implications together, but the person, as subject of intellectual and existential relations. It is the person, set in his or her deep intellectual and existential context, who gains insight and discernments into statements that reason alone would be unable to fully understand: why justice and compassion can be found harmoniously in God; why God’s unity does not contradict the mystery of a three-person communion; why the mystery of Incarnation and the wisdom of the Cross contain the essential answers to the central questions of human existence; why the disciple of Jesus can reasonably and freely decide to give up his or her life in order to get it back (cf. Mt 10,39).

2. Unity of Knowledge and Unity of Life. The harmony between faith and reason in a believer’s consciousness is experienced in every realm of knowledge and behavior. The unity of knowledge recalls the idea of a “unity of life,” understood as the capacity that faith has of unifying a given praxis (cf. Christifideles laici, n. 59). This is achieved fully when the light of faith illuminates the “way” to carry out a given task by guiding intellectual activity and inspiring the choices and objectives to be fulfilled. In the same way, intellectual activity collaborates to “give reason” to one’s faith, allowing it to embed its roots even further and granting the tools to talk about it in an appropriate way. Focusing on the person as the subject of the action, the circularity faith-reason becomes a circularity between charity and freedom. One’s orientation towards a praxis (the unity of knowledge as act of the person) which helps unifying various fields of knowledge, now finds its completion in the believer’s virtue of charity, as “form” of human acting (in this respect, Christian theology speaks of charity as “form” of all the other virtues). At the same time, love for God and for neighbor motivates the subject to a new and deeper free intellectual commitment, which in turn becomes a new charitable service.

For a Christian believer, one of the results of such unity of life is the desire to understand better, in a parallel and balanced way, both the subject-matter of his or her professional life and the philosophical and theological doctrine related to that subject, whose knowledge becomes necessary to carry out that activity with a “Christian mind.” The reasons for this way of acting are similar, on the level of personal synthesis, to those motivations of opportunity suggesting the presence of theology close to other disciplines within a university campus. When both scientific knowledge and knowledge by faith are studied in depth in a parallel way, the believer is prepared to receive some mutual, fruitful “provocations” coming from both fields of study. If carried out in respect for the methodological rigor proper to each field and moved by the love of truth, this more in-depth study will strengthen the unity of life of the subject. The life of faith can thus develop, without putting reason into parenthesis, by providing credible answers to doubts or perplexities that could come along in the course of one’s intellectual maturation. Without this fruitful tension, doubts and bewilderments could remain as such, especially when the philosophical and theological bases to provide a synthesis are superficial or insufficient. Intellectual life can be helped by faith to maintain a humble attitude, one associated with all true knowledge, thus keeping reason away from the path of relativism, of ideology, or of personal pride. In the logic of such synergy, however, the knowledge of faith has an original and specific character. It is that the deepening of faith does not depend only on the intellectual effort made by the subject in acquiring specific notions or doctrines. It depends above all on the love with which the believing subject looks at the known object, and on the degree to which the subject puts into action what he or she confesses by words. What applies to all kind of knowledge with respect to the interest and personal involvement necessary for every true intellectual insight, also applies, and in a very special way, to the intellectus fidei towards Revelation, because God and the things related to Him can be known only through charity.

The Christian faithful, undivided subject of a unity of knowledge that has now become unity of life, find themselves, in Christ, fully absorbed in that exitus-reditus according to which creation, coming from God, returns to God. This approach represents one of the strongest biblically supported pictures of unification of Christian thought (see above, II.2). The achievement of a mature synthesis between reason and faith represents a condition necessary for participating in that divine plan of summing up and reconciling all things in Christ. It is the great plan of salvation by which the Son, through his true humanity, returns all created things to the Father, with the power of the Spirit (cf. Ef 1:10; Col 1:19-20). The Second Vatican Council has affirmed: “May the faithful, therefore, live in very close union with other men of their time and may they strive to understand perfectly their way of thinking and judging, as expressed in their culture. Let them blend new sciences and theories and the understanding of the most recent discoveries with Christian morality and the teaching of Christian doctrine, so that their religious culture and morality may keep pace with scientific knowledge and with the constantly progressing technology. Thus they will be able to interpret and evaluate all things in a truly Christian spirit.” (Gaudium et spes, n. 62). Because of this “Christian gaze on the world” generated by listening to the Word of God, the believer is called upon to evaluate, without prejudice, the new problems raised by science and culture, to understand the changes of view that such innovations have brought about, and to guide techno-scientific progress according to the light of faith. The guarantee that the cultural and social drawbacks of a synthesis made “from inside one’s faith” do not imperil the legitimate autonomy of temporal realities, relies on two central tenets: that the truth of the Revelation cannot contradict the truth of reason, and that all that is meant by the adjective “Christian” also means, precisely for being Christian, all that is authentically and deeply “human.” (cf. Gaudium et spes, n. 41).

However, the synthesis between faith and reason that the believer has to reach does not imply only the moral orientation of a specific discipline having a particularly critical content. If the importance of such orientation is clear enough in fields such as medicine, economy and law, in which the relationship to the dignity of the person is particularly obvious, the unity of knowledge that comes from the synthesis of reason and faith is in reality called to something more. There are no aspects of reality, programs of study, objectives of scientific research, ways of teaching, that can remain unrelated to, or detached from the service to the society and to the human person. To relate science and wisdom is not only to bring together the culture of the means with the culture of the ends. For a believing faithful to provide a synthesis between science and wisdom is above all to find, and explain to others, the way in which each earthly task and human work comes to join in the mystery of Christ, uncreated Wisdom, by allowing each activity, manual or intellectual, to participate in His reign. “Strictly speaking, we cannot say that there is any noble human reality that does not have a supernatural dimension. The divine Word has taken on a complete human nature and has consecrated the world with his presence and with the work of his hands.” (J. Escrivá, Christ is passing by, Dublin 1985, n. 120). It should not be surprising, then, that respect for the legitimate autonomy of the created realities does not prevent a “Christian” way of doing research, of working or of teaching. The desire to place Christ at the summit of all human activities (cf. Jn 12:32) leads each believer to try to promote, in his or her own professional and intellectual activity, a profound unity of knowledge supported by an authentic unity of life centered around charity. Love is, in fact, the end towards which the truth itself aims, just as any effort does to look for truth, understand it or teach it. In the perspective of a life of grace, the Christian faithful know that, in order to sanctify human work, the practice of human virtues is not sufficient. The practice of theological virtues is needed as well. These virtues, constantly supported by the life of grace and enhanced by the gifts of the Holy Spirit, will inspire any believer to elaborate a “Christian way” of thinking and working: in economy, medicine, law, art, science or technology, aware that this is nothing other than a truly human way of living. This is just the way in which Christ carries out, through the sanctified work of believers, the mission to lead and gather, in the communion of the Trinity, a world that the infinite and simple perfection of God put into being as an ensemble of finite and multiple varieties.

Documents of the Catholic Church related to the subject: 

Abbreviations and complete titles of the documents

Gaudium et spes, 62; John Paul II: Discourse to the students and Faculty members of the University of Turin, Turin, 3.9.1988, ORWE 10.10.1988, pp. 3-4; Letter to Director of the Vatican Observatory, 1.6.1988, OR 26.10.1988, pp. 5-7; Discourse to University Teachers for their Jubilee, Rome, 9.9.2000, ORWE 13.9.2000, pp. 2 and 9; Discourse to the Pontifical Academy of Sciences, 13.11.2000, Papal Addresses pp. 385-388. Fides et ratio, 5, 27, 40, 81.


E. BERTI, L’unità del sapere in Aristotele (Padova: Cedam, 1965); A. BLOOM, The Closing of the American Mind (New York: Simon and Schuster, 1987); M. BUBER, Between Man and Man (London: Collins, 1961); E. CANTORE, Scientific Man. The Humanistic Significance of Science (New York: ISH Publications, 1977); G. EASTERBROOK, “Science and God: a Warming Trend?,” Science 227 (1997), pp. 890-893; G. GISMONDI, Fede e cultura scientifica (Bologna: Dehoniane, 1993); G. GISMONDI, Scienza, coscienza, conoscenza. Saperi e cultura nel 2000 (Assisi: Cittadella, 1999); R. GUARDINI, Letters from Lake Como. Explorations in Technology and the Human Race (1926) (Grand Rapids (MI): Eerdmans, 1994); R. GUARDINI, The End of the Modern World (1951) (Wilmington: ISI Books, 1998); D. LAMBERT, Sciences et théologie. Les figures d'un dialogue (Namur - Bruxelles: Presses Univ. de Namur - Lessius, 1999); J.F. HAUGHT, Science and Religion. From Conflict to Conversation (New York: Paulist Press, 1995); M. HELLER, The World and the Word (Tucson: Pachart, 1986); A. MACINTYRE, Three Rival Versions of Moral Enquiry. Encyclopedia, Genealogy, and Tradition (London: Duckworth, 1990); K. JASPERS, The Idea of University (London: P. Owen, 1965); J. MARITAIN, Distinguish to Unite, or, The Degrees of Knowledge (1932) (Notre Dame (IN): University of Notre Dame Press, 1995); J. MARITAIN, Education at the Crossroads (1943) (New Haven: Yale University Press, 1974); N. MURPHY, G.F. ELLIS, On the Moral Nature of the Universe: Theology, Cosmology and Ethics (Minneapolis: Fortress Press, 1996); J.H. NEWMAN, The Idea of a University (1852) (Chicago: Loyola University Press, 1987); B. NICOLESCU, Manifesto of Transdisciplinarity (Albany: State University of New York Press, 2002); J. ORTEGA Y GASSET, Misión de la Universidad (1930), in “Obras completas”, 12 vols. (Madrid: Alianza Editorial, 1987), v. IV, pp. 313-353; M. POLANYI, Personal Knowledge. Towards a Post-Critical Philosophy (1958) (London: Routledge, 1998); M. POLANYI, Science, Faith and Society (Chicago: University of Chicago Press, 1964); M. POLANYI, The Tacit Dimension (Gloucester (MA): P. Smith, 1983); J.C. POLKINGHORNE, One World: The Interaction of Science and Theology (Princeton: Princeton University Press, 1986); RIGOBELLO ET AL. (eds.), L'unità del sapere. La questione universitaria nella filosofia del XIX secolo (Roma: Città Nuova, 1977); A. SALAM, Unification of Fundamental Forces (Cambridge: Cambridge University Press, 1990); E. SCHRÖDINGER, Science and Humanism (Cambridge: University Press, 1951); C.P. SNOW, The Two Cultures and the Scientific Revolution, The Rede Lecture (Cambridge: Cambridge University Press, 1959); C.P. SNOW, Recent Thoughts on Two Cultures, An oration delivered at Birkbeck College, London, December 12, 1961 (London: Birkbeck College, 1962); C.P. SNOW, The Two Cultures and a Second Look. An Expanded Version of the Two Cultures and the Scientific Revolution (Cambridge: Cambridge University Press, 1964); G. TANZELLA-NITTI, Questions in Science and Religious Belief (Tucson: Pachart, 1992); G. TANZELLA-NITTI, Passione per la verità e responsabilità del sapere (Casale Monferrato: Piemme, 1998), ch. V: “Università, interdisciplinarità e unità del sapere”, pp. 173-213; T.F. TORRANCE, Transformation and Convergence in the Frame of Knowledge. Explorations in the Interrelations of Scientific and Theological Enterprise (Belfast Christian Journal, 1984); T.F. TORRANCE, Divine and Contingent Order (1981) (Edinburgh: T&t Clark, 1998); K. WOJTYLA, The acting person (1969) (Dodrecht: D. Reidel, 1979).