Experience

The concept of experience possesses a multiplicity of meanings and is used in very different contexts; therefore, it is highly problematic and difficult to analyze. Nevertheless, and as a premise to our following explanation, we can immediately and clearly identify two precise meanings.

In the first place experience constitutes the point of departure of our knowledge, since it provides the "data" that theoretical knowledge will attempt to apprehend and explain. This role appears as particularly evident when the term "experience" is taken to mean "sensible knowledge of external reality." This applies to the natural sciences, and in a different manner, also to human sciences, as long as they have a sufficient empirical base. If we except the more radically idealist positions (among which we can include the more abstractly rationalist ones), such priority of experience is recognized practically by all philosophical currents, which coincide by pointing out that it is the origin of all our knowledge. In the second place, to experience is entrusted the task of being "the criterion of validity" of our knowledge. In this case, obviously, we do not refer anymore to sensible knowledge, but to the theoretical knowledge, which constitutes science in a wider sense. Now the problem is posed on the validity of such knowledge, which goes beyond the empirical data and includes formal theoretical elements. The question is then whether, and in what way, experience may constitute a basis which would allow us to judge the validity of all knowledge, now understood in its widest sense.

The fulcrum of the epistemological problem is then the following: can experience constitute a solid foundation for science? Or, instead, is it human reason the only able to capture reality and those necessary relations which science deals with? In the first case, we should also ask whether experience, in some way, can "communicate" its trustworthiness to reason and science. An epistemological clarification of the notion of experience, in order to be useful to the issue of the relationship between science and religion, should begin by exploring the semantic field of this notion, with the aim of elucidating the different problems included there.

I. The Semantic Plurality of the Notion of Experience

Part of the "problem of experience" is represented by the fact that its semantic field is extremely wide. Among "lab experiences", the "human experience" acquired through the prolonged exercise of a practical or manual activity, and the "experience of physical or moral pain," just to make three different examples, there exists a serious diversity. At a first sight, it seems difficult to reduce these different meanings to a primary, unique sense. Philosophical literature arrives at enumerating an enormous variety of meanings, depending on the assumed perspective (epistemological, psychological, existential, etc.) and of the dimension of knowledge taken into consideration. Here we will summarize some among the most important ones.

Experience as an act of knowledge. From a more direct epistemological point of view, "experience" makes reference to a certain act of knowledge: it could be understood as the immediate perception of something concrete (cf. Giannini, 1987, p. 12), or as the knowledge of a particular object (cf. Kessler et al., 1973, p. 377). Experience could also refer to at least one part or dimension of knowledge, for example to an non-isolated element of passivity which seems present in every human knowledge (cf. Alquié, 1970, p. 13). From this point of view the question of determining which type of knowledge is accepted as "experience" would remain open. That is, experience may be a knowledge of sensitive-type only, as it is often affirmed in the contemporary philosophy of science, and in the empirical-type positions in general (experience will then be the "sensory basis" of the direct, observational knowledge of the world: F. Dretske, 1995, p. 261), or, in a more general way, experience may be the knowledge of a certain sphere of reality acquired in a personal, direct and immediate way. Only in this second case it is possible to speak of internal, intellectual, psychological and moral experience.

Experience as the content acquired by an act of knowledge. The word experience can be referred also to the content acquired by an act of knowledge: it is then referred to as "experiential data." The experience denotes, in this case, not only the material content of such knowledge but the "modality" with which certain elements are presented to our knowledge: we affirm, then, they are data of experience, or even knowledge acquired from experience, not conclusions derived or deduced from another different knowledge, nor mere opinions or conjectures. In this sense, experience appears as an original "self-donation of individual objects" (Husserl, 1948, p. 23).

Experience as a field of knowledge. In a derived way, the term "experience" seems to also indicate reality itself, or a certain area of reality, insofar as it is accessible by our perceptive abilities: "the world of experience" in contrast to the world of thought or of ideas. Experience is presented as the "reality immediately present and affirmed on the basis of presence alone" (Bontadini, 1995, p. 34). However, different currents of thought discuss whether this reality is of an exclusively physical and sensible character, or it includes also realities which transcend the empirical level.

Experience as becoming experts. Experience also means a process protracted through time, through which we can learn or acquire ability or practical competence, a permanent knowledge which is reliable and objective, the result of a series of circumstances that the subject "has lived". This corresponds to one of the original meanings of the term "experience," that is, every process in which one learns "on his or on her own" by observing and doing, as opposed to learning as a consequence of theoretical reasoning. This process is a complex one, through which the different contents we apprehend from reality succeed in constituting a stable knowledge, that the subject assimilates and makes his or her own. It could be both a theoretical and a practical knowledge, even if, traditionally speaking, the term "experience" does not indicate a universal theoretical content, but rather expresses the ability or practical disposition to fulfill certain acts, to judge or recognize events, situations, etc.

Experience as practical dimension. Such an acquired experience concerns not only "knowledge" in the strict sense of the word, but it also involves practical and existential dimensions. It describes an acquired capacity related to one's practical behavior, and so indicates a "familiarity with some matter of practical concern, based on repeated past acquaintance or performance" (Heat, 1967, p. 156). It is possible to refer the term "experience" also to the totality of knowledge or to the dispositions that it provokes in the subject, to his or her social and technical competence (cf. Kessler et al., 1973, p. 373), participation in situations that bring about a personal enrichment. It is in this area that we use to place the "experience of life" (Ger. Erleben).

Experience as a criterion of validity. On a gnoseological level, experience can also indicate a method or a judgment about the validity of the same contents of knowledge, a method of verification, or even what is claimed to be the ultimate criterion of truth (cf. Brenner, 1999, p. 400). Science "checks in the experience" its own affirmations and theories. This is maybe the more usual meaning of the term in the context of the scientific method, heir of Galileo's teaching of a science whose conclusions come "from sense-experiences and necessary demonstrations" (Letter to Madame Christina of Lorraine, Grand Duchess of Tuscany, 1615, in Discoveries and Opinions of Galileo, ed. by S. Drake, Doubleday, Garden City (NY) 1957, p. 182).

Experience as anthropological and existential dimension. It is possible to make reference to experience also from a more general anthropological point of view. In this sense, it concerns not only the objective dimension of knowing something real, insofar as it is external to the subject, but also a personal knowledge, insofar as it is "experienced" by the subject. Experience can be considered, then, from the point of view of the conscience or awareness of the subject, also in relation to the affective emotional and intentional dimensions, understood both in a specific sense (for example the experience of pain), and in a general sense (the experience of life). It may then be defined as the perception of states and contents of conscience, and therefore as the same determination of the conscious life of the Self. On the anthropological level, and in relation to more markedly transcendent dimensions of the person, we can finally speak of moral experience, religious experience and mystical experience.

This multiplicity of meanings and of areas makes the philosophical analysis of this notion particularly difficult to carry out. To the different perspectives that can be assumed when considering experience (experience as "data," as "act," as "content of knowledge," as "process" and as "conscience"), we must add the different philosophical opinions on its nature and value: experience can be considered as something purely sensitive, empirical and immediate, or as the result of a complex elaboration, which can include also theoretical and intellectual dimensions; something unique and incommunicable, or instead equipped with a certain universality; passive and receptive, or resulting from an active elaboration from the part of the subject. The different positions are at times in contradiction among themselves, also concerning the meaning of the term: some authors identify experience with perception, even purely sensitive, and some consider experience as the result of a complex and intricate process which includes all human capacities and faculties. Consequently, the appeal to experience made in different areas, such as science, philosophy, or theology, run the risk of a certain non-communicability, because of a disagreement about the essential characteristics to be attributed to it. At the same time, the centrality and the potentiality of the notion of experience is evident. It is one of the most important interdisciplinary categories, towards which many diverse areas of knowledge show sensitivity and attention.

With the aim of most accurately evaluating the basis on which we can eventually build a common and not ambiguous comprehension of experience, it is necessary to appeal to the word's etymology and briefly describe the evolution the "problem of experience" has undergone during the main steps of philosophical thought.

II. Etymological Aspects: Experience as a Process of Pre-Scientific Knowledge

1. The Two Original Meanings of the Word "Experience". The original meaning of the term "experience" is worthwhile being considered here, even if it had initially no special philosophical value. The Latin term experientia (from experior, "to put to the test," "to attempt") indicates in the first place a "test" or an "attempt." Starting from this meaning, experiri can indicate, in second place, also the knowledge or ability deriving from such a test. Experientia means then the ability and the knowledge acquired after having tried a certain situation or made certain attempts: in this sense, someone is said to be an "expert" or an "experienced" person. The semantic field to which this term was applied in the past was very wide: examples are frequent in classic literature referring to military actions, to personal strength or courage, to friendship, etc.

The two primary meanings of experience, as "test" and as "knowledge or acquired ability," are already present in the Greek word empeiría, (from which the Latin experientia derives) and in its root peîra (to test, to attempt). From this latter verb derives also the unusual Latin verb perior , at the origin of the words periculum (test or difficulty), peritus (expert) and peritia (test, control). It seems also clear that a relationship exists between emperiría and the Greek verb peiro (to go through), or its root per, common to both, which contains the meaning of "penetrating" or "traversing." Experientia would thus recall the idea of what has been proven in a specific and certain manner, but, in the end, also what has been proven in a personal way, because the subject "has passed" through such a situation. We are in front of a notion of "pre-scientific" character, with a concrete and practical meaning, but nevertheless very flexible.

2. The Meanings of Experience in Ordinary Speech. The two original meanings are still present in ordinary speech, where the term experience designates again a test and the knowledge we acquire from it, and it is applied in many fields of human activity, practical, sensitive or affective. If the term seems today to recall primarily the "scientific experience," it is because science represents the area of human knowledge in which any "test" is conducted following a specific methodology and with a particular rigor. For those thinkers that reduce human knowledge to scientific knowledge, the term experience suffers a corresponding semantic reduction. Nevertheless, its anthropological and existential dimension are still well present in today's culture.

In ordinary speech it is common to consider experience as the accumulation of knowledge or of ability obtained through tests or attempts, both in the theoretical and practical sense (for example, in estimating the risks or the convenience of particular circumstances, in reaching a judgment from some clues encountered in analogous circumstances, etc.). Indeed, the epistemic weight of experience is undeniable: even having the meaning of a methodical or systematic acquisition of knowledge, it does not indicate so much the end of a gnoseological-conceptual itinerary, but a capacity of intuition and discovery, a fast, efficacious, and almost unconscious way to reach a knowledge and a judgment without having to resort to strenuous reasoning and long verifications.

III. Epistemological Perspectives on Experience through the History of Philosophy

1. Experience in Greek Thought. In ancient philosophy the notion of experience enters in the epistemological discourse through the idea of disposition, or capacity, acquired through the tests and attempts protracted through time. It does not possess a central role from a gnoseological point of view, since it is never seen as representative of authentic knowledge (Gr. epistéme). For Plato (427-347 B.C.) experience is closer to opinion (Gr. dóxa), and as such, is a frequent source of error (cf. Gorgias, 462-463). Aristotle (384-322 B.C.) tries to introduce the notion of experience within the theory of knowledge. It is an experience always understood as personal enrichment on the cognitive level, and it is seen as the result of reiterated sensations, elaborated by memory, at the same time it begins to assume a positive role in the comprehension of what knowledge is. Experience (Gr. empeiría) appears as a necessary, previous step for art (Gr. téchne ) and for science (Gr. epistéme) (cf. Metaphysics, I, 1, 980b-981a; Posterior Analytics, II, 19, 100). It cannot however constitute "true" science: experience does not succeed in apprehending the reason, nor the necessity, of what it knows. It still does not represent a properly universal knowledge, but it is concerned only with the knowledge of individual entities: "For men of experience know that the thing is so, but do not know why, while others know the "why" and the cause" (Metaphysics, I, I, 981a, 28-30).

It is worth noting that the Aristotelian theory of experience differs from the way we address the problem today. In Aristotle's view, even if experience belongs to a gnoseology, it does so only at a purely descriptive level. The Greek philosopher does not try to justify the validity of knowledge obtained through experience, and even less its theoretical aspects, including practical art or science. Although "it is through experience that men acquire science and art" (Metaphysics , I, 1, 981a 4-5), and experience is the source for the first principles of all human knowledge, the primacy of experience is only chronological, not logical; and that because the validity of every knowledge is judged by the intellect, through one of its specific functions. On the other hand, there is some uncertainty in regard to the value to be attributed to experience: it seems to concern only the sensitive area, but in some way it is placed between the individual and the universal, providing everyone with the skill to act properly.

2. Medieval Thought: Experience as Original Modality of Knowledge. Ancient philosophy always considers experience as a particular process through which we obtain knowledge about something concrete and specific; it lacks a reflection on experience in a more abstract meaning, as the primary constitutive element of the act of knowledge as such. What contemporary science and epistemology call "to observe" or "to experiment," was expressed by Aristotle with different verbs taken from common speech, such as "to see," "to consider" or "to contemplate" (cf. Bourgey 1955, pp. 37-38). Aristotle does not employ any specific term to express the empirical origin of knowledge in a general and conceptual way. This new meaning of "experience" was introduced in the Middle Ages.

Besides keeping the two meanings present in Greek thought, Medieval philosophy began to speak of experience to designate the elements of a direct learning which generate an accumulation of knowledge. There is here a gnoseological turn: experience is no longer considered as a particular, but approximate degree of knowledge. It now appears to be the foundation of the psychological and gnoseological description of knowledge, acquiring therefore a strictly epistemological value. Experience refers back to a contact with reality, from which it receives its own value. The term "experience" begins thus to designate, in a conceptual and theoretical way, the starting point and the origin of knowledge.

According to Roger Bacon (ca. 1214-1292), experience is mainly a "modality" of knowledge. He distinguishes between "knowledge by argument" and "knowledge by experience" (Opus Maius), differentiating thus between what is known by experience and what is known by other means: reason, authority, testimony of others, etc. However, and precisely from a theoretical point of view, the modality of knowledge by experience is at the basis of all knowledge. The term "experience" corresponds to an elementary type of knowledge from which all the others types derive their origin: in this way, experience becomes also the "foundation" of the validity of knowledge.

In this framework the proper and fundamental epistemological question rises for the first time: what characterizes experience as such?, which are the elements or the conditions of an act or content of knowledge, so that this act or content may be called "experiential"? In Scholastic philosophy, the answers will be fundamentally empirical, following the Aristotelian position. In Thomas Aquinas (1224-1274) experience appears primarily correlated to sensitive knowledge (experientia a sensu oritur —experience is born from the senses). The knowledge acquired by the senses constitutes somehow the primary meaning of the term, in line with its original etymological acceptation: to experiment is "to test" something in a manifest and evident way, as it happens, above all, in the sensitive test. Reference to senses, however, is not exclusive. In Medieval philosophy the distinction between two types of experience is frequently present. For example, Alexander of Hales (1185-1245) spoke of "sensitive experience" and of "intellectual experience" (cf. Summa Fratri Alexandri , II, I, n. 119, ad 3^um), while Roger Bacon spoke of "sensitive experience" and "experience of inner illumination" (cf. Opus Maius, I, 10).

Clearly affirming the priority of sensitive experience, Thomas Aquinas recognizes that "the name of experience is transferred to intellectual knowledge also, like the name of the senses do, such as sight and hearing" ( De Malo, q. 16, a. 1, ad 2^um). The common element between these two areas, senses and reason, which allows the analogy of experience, will be for Thomas the "individual entity." The proper object of the human intellect is what is universal: nevertheless, it is able to apprehend also what is particular, both returning to the sensitive images of memory and knowing its own specific acts, including the act of its own existence (cf. De Veritate, q. 10, a . 8 ad 8 ^um) and other faculties' acts, such as affectivity, passions and will (cf. Summa Theologiae, II-II, q. 97, a . 2, ad 3^um). It is possible, therefore, to speak in a proper (but derived) way of inner intellectual experience, or even of personal experience.

At the same time, experience progressively looses the somehow "subjective" character which it possessed in Aristotelian philosophy. For Aristotle, the acquired experience belonged to the subject, as a habit or capacity to confront favourably similar circumstances of life. The more abstract gnoseological consideration of experience, understood as origin and modality of knowledge, renders experience more "objective". One of the characteristic dimension of Medieval notion of experience is therefore its "passivity": experience is a knowledge in which the subject, above all, "receives", without fulfilling a proper (gnoseological) function. Experience is also presented as "intuition", emphasizing the analogy with sensorial vision and as opposed to reasoning or deduction. The objectivation of experience, however, does not turn out absolute nor reductive. There is still room for inner experience, as in Aquinas' doctrine of "knowledge by connaturality" (cf. D'Avenia, 1992).

3. Experience as Radical Origin and Justification of Knowledge in the Modern Age . Medieval philosophy set the bases for the gnoseological turn of Modern philosophy. This turn first appears in William of Ockham

(1280-1349): experience is a "perfect intuitive knowledge," whose necessary objects are present and existing things. The object of experience is then the concrete and individual being, considered as a physical and sensible object. From that moment onward, experience is ever more seen as reduced to sensorial perception, as empiricism would affirm in the following centuries. For John Locke (1632-1704) the intuition of external things ("sensation") and that of internal acts ("reflection") constitute the two elements of knowledge. However, since exterior sensibility does not represent but a particular state of conscience of the subject, David Hume (1711-1776) unifies both elements in the "impressions," and "ideas" are considered to be just as a pale reflection of them. Hume concludes that -except for mathematical ideas and concepts- only impressions are able to guarantee true knowledge, as they are the only original content of experience.

This evolution shows the epistemological root of the Modern notion of experience. It is no longer a simple element of knowledge (even if original), but the only ground able to justify its logic and rational validity. That pretension was absent in the Medieval formulation of the problem. For Scholastic thinkers, the reference to experience, as the basis of knowledge, would have been a way to check, in each science, the correctness of reasoning. Experience was an epistemological notion, but only from a methodological perspective. Modern thought, instead, moves towards a justificationist and purely deductive logic. Following the Cartesian program which sets "certainty" as the fundamental epistemological value, the aim is to derive all of our knowledge by logical deduction, that is from the data we start with (experience). The non-feasibility of such pretension will appear later, in a dramatic way, in the skeptical outcome of Hume's philosophy.

Another conceptual turn is here achieved. If in the Classical world experience was conceived as a "process of knowledge", and in the Medieval thought as a "modality of an act of knowledge" (or also as the reality manifested through it), Modern philosophy emphasizes experience as a "mental content". A subject's experience will be properly defined as the ideas or concepts directly obtained from reality, without any intellectual or reflexive mediation. These "elementary empirical unities" are what the philosophy of science of the 19th century will call the "empirical basis" of science, a primary and unconditional element called to justify the validity of the theoretical elaboration of science (cf. Abbagnano, 1998, p. 395).

The Modern Age sees also the development of another notion of experience, which converges with the justificationist perspective. For the authors whose interest is centered in science, as Francis Bacon (1561-1626) and Galileo Galilei (1564-1642), experience is first of all, the process through which it becomes possible to reach a true scientific knowledge. Experience becomes then synonymous with the experimental method, or even more with verification or experimental proof. That process is not purely sensible; it includes an abstract and intelligible reflection, and even the ability to "read" the mathematical language in which the "Book of Nature" is written (cf. Galilei, The Assayer, in Works of Galileo Galilei, Florence 1968, vol. VI, p. 232).

Galileo is considered as the first author to achieve, in a fulfilled and aware manner, the experimental method, mainly in his kinematical studies. Scientific experience, different from simple common observation, demands accurate observations, guided by a theoretical project, which tries to determine the relevant aspects of a particular problem. The experimental method thus conceived, put into practice and perfected during the 17th century by Galileo, Christian Huygeens (1629-1695), Robert Boyle (1627-1691), Niels Steensen (138-1686), Blaise Pascal (1623-1662), Isaac Newton (1642-1727), and many others, had in Modern Age its first theorist in Francis Bacon. Experience is not simply the beginning of knowledge (this would be the simple observation, unable to preserve human knowledge from error), but first of all "the method" to reach a valid knowledge. 

" Sed demonstratio longe optima est experientia; modo haereat in ipso experimento - Experience is the best demonstration, as it follows from the same experiment"  (Novum Organum, I, 70). The privileged form of experience is then the experiment, namely the experience conducted not "by chance," but aimed at and organized with the help of reason (cf. ibidem, I, 82). Bacon tries to determine the precise method through which reason can arrive at certain truths: to gather the greatest possible number of observed cases, select the useful ones, organize them and group them in a rational manner on tables of frequency (cf. ibidem, II, 11-13).

From this perspective, experience does not represent a precise mental content, but rather a method able to apprehend the original elements of reality. However, some "critical" dimensions will progressively emerge. The method of experimental verification becomes now the criterion to determine the validity of every content of knowledge obtained through different ways, from observation to rational activity. This will be particularly evident in Immanuel Kant (1724-1804). Even if starting from an empirical notion of experience, as data or sensible impression, the research of a trustworthy foundation of knowledge will lead Kant to see experience (now in a "technical sense") no longer as a "content" passively received from the mind -according to the empirical vision of knowledge- but as a synthesis between a material element ("the empirical intuition") and a formal element able to operate a synthesis of perceptions according to a universal rule (the "a priori categories"). The categories unify intuitions and allow the formulation of valid judgments that are universal and necessary, which he will call "synthetic a priori." According to Kant, only that synthesis allows us to speak of "true" knowledge. Experience becomes synonymous with knowledge; it is no longer a knowledge identifiable with reality in itself, but it now indicates all justified and appropriate knowledge.

After the idealistic parenthesis, this program aimed at seeing experience as the ultimate instance of justification of all our pretensions of knowledge reaches its higher expression in logical Positivism, and in most part, of the philosophy of science of the 20th century. The Vienna Circle tries to unify the notion of purely empirical experience sustained by British philosophers -Hume in particular, and then Ernst Mach

(1838-1916)- with the logical-linguistic instances of the Tractatus Logico-philosophicus by Ludwig Wittgenstein (1889-1951). A common characteristic among these views was the attempt to reduce experience to the ultimate original data, now no longer considered problematic because of lacking every component of thought. Hume reduces experience to impressions that are so punctual that they are not able to last in time; for Mach the sensations constitute the "fundamental empirical unities", and they are received as "facts" (Ger. Sachverhalte)  by Wittgenstein. Rudolf Carnap (1891-1970), the main representative of logical Positivism, several times and without achieving any success, will try to build the totality of science and of human knowledge starting from "elementary lived experiences" only (ger. Elementarerlebnis), excluding as meaningless all that did not constitute an expression of pure logic, or had no direct foundation in empirical data.

The neo-positivistic vision of science, in spite of the failures that forced their proponents to repeatedly review their positions, reached a dominant position in the middle of the 20th century in the philosophical reflection on science (the so-called received view or standard view: cf. Putnam, 1962; Suppe, 1974). Among its main postulates there was the radical distinction between theory and observation. The main epistemological question (now almost reduced to "methodology of science") was therefore relating theory with the empirical contents given by experience. However, the inner problems of this view, together with an ever wider consideration of other forms of experience and knowledge coming from the new philosophical developments made during the 19th century, forced philosophers of science to a radical re-thinking of their own positions in the second half of the 20th century.

4. Aspects of Contemporary Thought: Experience as Personal Life and Criticism to Neo-Positivism. Through the contribution of idealism —which will exalt primarily the most subjective aspects of experience— the 19th century will gradually reach a strong call to the "unity" of experience. On one side, more importance will be attributed to non-sensitive dimensions of experience, beginning with the interest for the "sciences of the spirit" and their "forms of experience" which lead to distinguish between internal, sensitive, emotional, psychological, religious, scientific experience etc. On the other hand, especially thanks to the contribution of Romanticism, experience is apprehended as something indivisible, which embraces every aspect of personal life, such as "life experience" (Ger. Erlebnis) and "historical experience", which encloses in itself the totality of what the subject lives and experiences in the world and in the course of history.

This position will be traceable in many philosophical currents of the 20th century, such as spiritualism, existentialism, phenomenology, and pragmatism, although very distant among themselves. All of them affirm the unitary character and the personal value of experience. The re-evaluation of historical living will find voice and development, also in dialogue with the sciences, in the thought of Henri Bergson (1854-1941) and his metaphysics of experience. The American pragmatists, such as William James (1842-1910), Charles S. Peirce (1839-1914) and John Dewey (1859-1952), have insisted on the open character of experience, maintaining that it cannot be reduced to the simple sensorial perception, nor to what the subject receives on the level of knowledge, but is presented as the relation between the living being and his physical and social surroundings.

Edmund Husserl's (1859-1938) phenomenology tries to return to a pure, original experience in which the objects should be given with evidence, as they are in reality; in actual experience, however, it is not possible to dissociate the original reality from the pre-conceptual "horizons" which condition their comprehension. The existential and hermeneutic currents, particularly Martin Heidegger (1889-1976), Hans Georg Gadamer (1900-2002) and Paul Ricoeur (1913-2005) again highlighted the historical character of experience, which is not given without a pre-comprehension of the world (which is itself an object of experience) and the link to a tradition, as subject of specific interpretations of reality.

Some other criticisms to the neopositivistic view of science, that considered science as having a foundational moment (experience) independent from any theoretical assumption, proceed from the new philosophy of science. These criticisms, anticipated by Pierre Duhem (1861-1916) and Michael Polanyi (1891-1976), have been thoroughly elaborated from different perspectives in the second part of the 20th century. Karl R. Popper (1902-1994) denies the possibility of an empirical verification of theoretical assertions and proposes a conjectural and falsificationist vision of science. Norwood R. Hanson (1924-1967) has pointed out that every assertion which starts from observation is inevitably "theory laden." For Thomas S. Kuhn (1922-1996) science operates always within a "paradigm," which is constituted also by historical, social and ideological factors. Finally, the criticism of Willard V.O. Quine (1908-2000) of "the two dogmas of Empiricism," denies the possibility to reduce the meaning of theoretical elements to a logical set of observed terms. All these proposals have as their common characteristic the refusal of the possibility of a "pure" experience, able to provide an achieved foundation for scientific knowledge.

In the last decades of the 20th century the influence of hermeneutic currents reached the field of philosophy of science, giving origin to positions about knowledge and its possible justification in experience that are largely relativistic. Its main exponents are Richard Rorty (born 1931), Jacques Derrida's (born 1930) deconstructivism, and sociology of science (cf. Banres, 1974; Bloor, 1976). Experience no longer appears as the original contact with reality, the paradigm of objectivity, but is seen as a constructed result of multiple personal and social influences.

IV. Experience in the Method of Science

The consideration of experience has a very particular role in the scientific study of the world, a study often denominated as "experimental science." As we have already mentioned, in modern science the recourse to experience acquires the role of "method" through which it is possible to obtain a valid knowledge of reality. The question of what such "validity" means, however, always remains open: whether it is a logical justification in a rigorous sense, a "trustworthiness" of results, a practical correspondence, etc.

Ancient science was already founded on experience, that is on the recourse to evident data gathered through observation as its starting point. Such practice can be found in the writings of the Corpus Hippocraticum which tradition dates back to Hyppocrates of Kos (around 460 B.C.), in Aristotelian biology, in medicine and in Hellenistic optics (cf. Lloyd, 1996). Also the methodology of ancient astronomy, condensed in the expression sóizein tá phainómena (to save the appearances), so often interpreted nowadays in an instrumentalist way, implied the recourse to observation as the necessary term of comparison to assume the validity of a theoretical system.

The practical appeal to experience has then been a characteristic of science from its birth. Beginning with the 17th century, however, its role within the scientific method is transformed. There was, from one side, a progressive intensification of the "inductive" dimension of science. Theory was seen as the result of a generalization of the data of experience. On the other hand, experience no longer appears only as an "observation," but also as an "experimentation," acquiring new characteristics. We must consider briefly two questions, both related to a fundamental problem of scientific epistemology: the relationship between theory and experience.

The first question concern the problem of induction. Beginning with the 18th-century Enlightenment, scientific methodology has often been presented as purely inductive, following Francis Bacon's theoretical program exposed in his Novum Organum. According to Bacon, inductive methodology is the only one which can provide a true knowledge, since it is the only one to reach conclusions based solely on experience: a "scientific law" can only be obtained as the result of an empirical generalization, that is observing how the facts are presented in experience, and extracting from them the "general rules" of their behavior. Many among the founders of modern science would have followed this methodology, beginning with Galileo (see the experiments for the determination of the law of falling bodies) and Isaac Newton, who explicitly affirms not to make hypothesis (hypotheses non fingo).

The logic of the inductive method, nevertheless, is far from being clear, and was already placed under criticism by Hume. The Empiricism of the 19th century, with John Stuart Mill (1806-1873), tried to re-evaluate induction through the introduction of opportune "canons of inductive reasoning," that is, through the consideration of "similarities", "differences," "concomitant variations" and "residues," but the difficulties of such a method, when applied in an isolated and strict sense, have repeatedly emerged.

In the 20th century several attempts were made to "justify" induction. Many of them resort to the idea of probabilistic induction, understood as a method apt to determine the degree of probability of the confirmation of a hypothesis (cf. Carnap, 1950; Hintikka, 1989). The criticisms of Popper (1963) and others, but also the revision of the historical presuppositions which placed the inductive method in the origin of science (cf. Koyré, 1939), have generally led to the preference of the hypothetical-deductive schema, already proposed by authors such as C. Bernard (1813-1878) and P. Duhem. Scientific theories have, above all, a hypothetical character, and should be controlled with the help of empirical data. In any case, experience constitutes the necessary point of reference for the determination of the validity of the theory.

The second question here concerns the logic of the experiment and its relationship with the scientist. In modern science the recourse to experience has been transformed passing from simple "observation," that is the gathering of casual or at least non-systematic empirical data, to "experimentation," which consists in selective and aimed observations, performed in particular conditions provoked by scientists themselves, with the goal of obtaining some specific empirical data, independently from possible factors that could modify them. Since Galileo, experimentation has thus become synonymous to scientific method. It would be wrong, however, to see experimentation as a direct and simple recourse to experience; it implies rather a series of theoretical presuppositions whose importance has been recognized always more clearly in modern science.

It must be recognized in the first place that experimental logic implies some epistemological and metaphysical presuppositions. One is the "regularity" of nature or the existence of laws of nature, which we may be able to discover and understand. A second presupposition is the validity of the analytical approach according to which it is possible to know an aspect of reality adequately and independently from those other aspects of reality which are related to it, that is, leaving them aside for methodological purposes. This last presupposition, which constitutes a characteristic and essential trait of modern science (cf. Agazzi, 1984), has been put into question today by the study of complex systems, which points out also the importance of synthesis, and the success of employing a certain holistic vision of reality, or at least of some parts of it.

Moreover, it is important to notice how experimentation implies in itself a fundamental theoretical component. Experimentation is always guided by an established plane in view of certain goals. So the tester asks nature certain "questions", while he or she disregards others. The scientist is guided by certain theoretical presuppositions, concerning for example the "elements of reality" with which he or she operates, or the conditions of observability of the facts one wants to find out; finally, the scientist has to interpret the experiment within a particular theoretical framework. Experimentation, therefore, is not placed as an indisputable element previous to science, but as the essential moment of research, in which a dialogue between theory and experience takes place.

From this point of view, the discussion which has taken place in 20th-century epistemology on the theory-ladenness of observation, although important, risk to remain sterile if viewed exclusively from a "justificationist" perspective, that considers experience as sensitive, purely objective and not interpreted data, trying to obtain a radical justification of a theory. The awareness of the multiple aspects of experience should allow a comprehension of scientific method which does not reduce it to a logical-formal elaboration having purely objective, empirical basis. On the contrary, the task of scientists must be presented as the research of an ever more in-depth comprehension of reality, able to integrate the objective and personal aspects of scientific experience.

V. Experience as a Religious and Theological Topic

The problems, but also the potentialities, we found in the philosophical notion of experience, in the gnoseological and existential domains, find ample reflection on the theological plane, in religious language and in the area of spiritual life. Here a twofold demand is registered. On one side there is the necessity of not reducing religion to a pure subjective experience, since it claims to have also an objective aspect; this is especially true in the case of the Judaeo-Christian religious tradition, where we find a number of objective contents proposed to the faith of the believers, and that God has revealed in history through words and actions (cf. Dei Verbum, n. 2). On the other side, the need is evident to underline the personal aspect of religious experience, which is realized and expressed through a profound existential living, as it is shown, for example, by the great religious relevance associated to notions such as conversion, salvation, joy, repentance, consolation, freedom, love, etc.

1. The Experience of the Sacred. The phenomenology of religion speaks of an "experience of the sacred" as of a "fundamental element of the structure of human conscience" (cf. Eliade, 1978). The history of religions has frequently asked whether the sensus religiosus has its roots in the original human experience as such, or rather it arises as the product of cultural choices, suggested or imposed by the same evolution of human society. Some have interpreted the human religious experience in "evolutionist" terms, as the passage from an absence of God, to totemistic fetish (cult of nature, of animals and of things), to idolatry, to anthropomorphism, and finally to an idea of transcendent divinity. Religious experience has been also interpreted in "functional" terms, hypothesizing that the idea and the experience of the divine changed in the course of history following the historical-social evolution of human beings, from hunting to agriculture, to shepherding up to the rise of organized societies. The phenomenological approach, that appears today to be the most correct, and whose object of research is not the human being insofar as a subject of evolution or transformation, but the human being insofar as human, also tries to understand when and why the religious feeling appears in human history. This last approach seems to conclude by attributing an original status to religion: Homo sapiens presents himself on the scene of the world both as a religious and a cultural being.

To religious experience belong many experiences, common to every human being. Among the most important are: the perception of one's own contingency, derived from the experience of nature, such as the strength of natural phenomena, the limitations of one's own physical life, the richness or lack of the fruits of the earth, etc. -all events out of human control; a sense of dependence and expectation, which is born from the inability to give an answer to the ultimate whys about one's origin and destiny, about the meaning of one's life and the desire of perpetuating it beyond death; the belief in the existence of an Absolute-Almighty (see God), located in the sphere of transcendence, who may possess the answers to those ultimate whys, and for this reason thought and invoked as the "Totally other" or the "Totally different" with respect to what the humans can know and experience. Perception of one's own moral conscience, in which everyone can read the judgment of one's own actions, and recognize the imperative to do good and avoid evil, also belongs to religious experience. Finally, according to some authors (cf. Cantore, 1977) there exists a perception of the sacred, stemming from the experience associated to the scientific study of nature, a kind of "religious" experience that the researcher feels as opening to a sense of mystery and of transcendence.

2. Experience and Biblical Revelation. Judaeo-Christian Revelation, because of its historical-salvific character, includes a strong call to experience. The people of Israel arrives at the awareness of the existence of God and of His attributes, primary (even if not exclusively) through what biblical theology calls "the religious experience of Exodus". In a more general way, in the great historical steps of Revelation «He so manifested Himself through words and deeds as the one true and living God that Israel came to know by experiencing (Lat. experiretur) the ways of God with men» (Dei Verbum, n. 14). The central message of Christianity, the incarnation of the Word of God, along with his death and resurrection, is understood by Jesus' disciples and the apostles as the result of a remarkable "experience of Christ" (cf. 1Jn 1:1-3). They live such a message and propagate it with the comfort of an "experience of the Spirit" (cf. Acts 2:1-11; 1Cor 12:2-3). The Apostolic Tradition is ever better known and deepened with the help of the Spirit, thanks to the teachings of the Church Magisterium and the study of the Word, and "through a penetrating understanding of the spiritual realities which the believers experience" (Dei Verbum, n. 8). Thus Revelation shows the two characteristic dimensions of experience, that is objective and subjective. The word of God is taught, heard and understood as a specific content presented to our external experience, and thanks to the witness we experience of those who live God's word. There is also an internal word, of which we make experience as well, a word we listen to within the heart, whispered by the Spirit, which internally reveals and allows us to welcome in our personal sphere what we have heard and seen externally.

In his classical study L'expérience chrétienne (1952), Jean Mouroux explains the modalities with which the great themes of Christian experience cross the books of the New Testament. The experience of vocation as a call of Christ, which deeply mark, both immediately and throughout one's lifespan, those who decide to follow him; the experience of repentance and conversion, caused in the listeners by the preaching of Jesus to the individuals and to the crowds; the experience of joy which characterizes unequivocally anyone who welcomes the divine word and begins to live its demands. The First Letter of John is very important in this respect. There Christian experience is presented in its inseparable and integral character: the experience of communion among human beings newly born as God's children, and with God, as source of intimate joy which must be transmitted to others (cf. vv. 1,3-4); the experience of knowing to be sinners before God and to have in Jesus Christ a salvation greater than our sins (cf. vv. 1,8-2,2); the experience of divine filiation, of the rights and demands it implies (cf. vv. 3,1-2); the experience of the presence of the Holy Spirit as the inner source of moral Christian life, and, conversely, the experience of Christian life as something capable of revealing the presence of the Spirit (cf. vv. 4,11-13). In the letters of St. Paul, the Holy Spirit appears to work in close synergy with the Christian faithful's life, through actions and attributions that involve the living and sensible experience of the believer: the Spirit dwells in the body sanctifying it (cf. 1Cor 6:19); it "seals" the believer and presides him or her as a pledge of a future inheritance (cf. 2Cor 1:22; Eph 1:14); guides the entire action of the children of God (cf. Rom 8:14); prays, groans and invokes by the mouth of the Christians (cf. Rom 8,15-26); brings about an authentic transformation-conformity, which the Christian faithful experiences the effects of, and that produces sensible fruits (cf. Rom 8:11.29; Gal 5:22).

It must be noted that the New Testament proposes Christian experience with the canons of "knowledge". Having had the experience of Christ (St. John), or living according to an experience of the Spirit (St. Paul) is, for the subject, a source of authentic knowledge: "He knows! He knows to have passed from death to life. He knows God and he knows Love. He knows he belongs to God, he knows to be in God and that God is in him; he knows to be in the truth and to possess eternal life. And if he reflects, he knows to know God" (Mouroux, 1952, p. 167). To have made the experience of the cross of Christ, in the sufferings, in the contradictions, and in the preaching of that which is retained as a scandal and a folly, allows Paul to penetrate in depth the logic of the message of Jesus, to understand his mystery (cf. 1Cor 1:21-25; 1Cor 2:6-15), to know him and therefore to act accordingly, without fear (cf. Phil 1:21; Phil 3:8; Col 1:24). The apex of this experience, to which every believer is called, is the awareness that while yet he lives, no longer he, but Christ lives in him (cf. Gal 2:20). The religious experience marked by the Christian message intends to maintain a clear connection with the universality of the human existential experience and therefore to lean on the latter for its communicability. The announcement of the Gospel is certainly the transmission of an experience -the experience of Christ and of his Spirit- but not according to subjective canons, because God's love "fully reveals man to man himself" (cf. Gaudium et spes, 22). Christ's announcement enlightens the truth of the deepest and universal human experiences and provides the answers all human beings are looking for.

The value that biblical language ascribes to experience does not lead us to conclude that one may speak of an "experience of God", in the empirical or immediate sense we may attribute to this expression. The Scriptures coherently teach, in the Old as well as in the New Testament, the invisibility of God, Someone of whom we cannot make any direct experience (cf. Jn 1:18). This holds also for the Incarnate Word, because the experience of God made by those who lived with him was mediated precisely by the humanity of Jesus. So we cannot speak, in a strict sense, of an experience of God, although the life of faith is without any doubt associated to a true experience of knowledge of what is from God and of what belongs to God. The life of the saints —may it suffice to remember the Augustinian itinerary reported by his Confessions— provides sufficient basis to affirm that. The contemplation and experience of divine things which theology calls mystic, is not foreign to it.

3. Experience and Theology. The use of the notion of experience in theology was subject to the course of events. Breaking the balance with which it was handled in the patristic and medieval ages, Martin Luther (1483-1546) moved the understanding of experience towards subjectivist categories. He intended to oppose a personal and existential reading of Scripture (somehow experiential) to a reading guided by the Church Magisterium, and proposed to understand the sacraments within the horizon of a personal and exclusive relationship of the faithful with God, not, anymore, as ways to confer God's grace through the ministry of the Church. The Council of Trent distanced itself from this doctrine, affirming that an individual and private experience could not be assumed as the ultimate and definitive criterion of personal salvation (cf. DH 1564). The philosophy of religion born in the climate of the Reformation, fed later by idealistic and romantic perspectives, interpreted the religious experience of humanity according to historicist categories. First Kant, and then Schleiermacher, assigned to Christianity the role of ideal apex of the historical development of religion. In a parallel way, on the gnoseological plane, Friedrich Jacobi, and in certain ways also Kierkegaard, proposed the idea that feeling represented the fundamental criterion of truth. At the beginning of the 20th century, William James (The Varieties of Religious Experience, 1902) will easily frame these, feeling and experience, within a pluralistic and pragmatist metaphysics. This orientation will enter, at least in part, into the Catholic world, through the modernistic movement. Although it had the merit to re-evaluate the existential and personal aspect of Revelation, the Modernism movement tried erroneously to present this personal dimension as opposed to its dogmatic content. By reducing the entire Revelation to experience, it arose the disapproval of the encyclical Pascendi (September 8, 1907) preceded by the decree Lamentabili (July 3, 1907), both due to the Magisterium of Pius X (1903-1914).

In the first half of the 20th century, the question of experience will find a double theological development. In the theology of the Reformed Churches, the role of experience was underlined through the proposition of an existential exegesis (Bultmann) and the radicalization of the priority of our experience of faith in Christ as the only criterion of comprehension of the Revelation (Barth). In Catholic theology, starting with Maurice Blondel (1861-1949), and even before with John Henry Newman (1801-1890), a number of authors tried to patiently rebuild a more balanced vision of the existential and personal aspects of faith. Among these, it must be mentioned the contribution of French personalism, especially Mounier, Mouroux, Bouillard, Marcel, and also the development of the dialogical philosophy of the Hebrew Martin Buber. The documents of the Second Vatican Council (1962-1965), Gaudium et spes in particular, offered the basis for the gradual recovery of the theme of experience, already no longer in the light of subjectivism or simple sentimentalism, but in the commitment and integral response of the person, with all his or her spiritual, psychological and emotional potentialities, to the call of Christ.

Among the main orientations of contemporary theology in this regard, at least two should be signalled, which rose within Fundamental theology as attempts to better explain the justification and communication of faith (cf. Blanco, 1996). The first starts with the "experience of man" and aims at anchoring the answers of faith to the questions posed by human conscience, even if sometimes this approach runs the risk of remaining confined within a finite anthropological horizon. One of these attempts is represented by the method of the correlations developed by P. Tillich, according to whom any person can apprehend the answers provided by Revelation only insofar as he or she has experienced the corresponding questions searching for a meaning. Other attempts were: the proposal of G. Ebeling to interpret every authentic human experience in terms of a religious experience; the proposal of K. Rahner about the existence of a transcendental experience in every human being, which points towards God in a non-thematic way (i.e., without necessity of any conceptual category), being it the fundamental measure of human opening to infinity; the justification of faith according to W. Pannenberg, as the answer to the experience of the totality of meaning. The second, less systematic orientation starts from the "experience of Christ," more precisely from the "experience of man with Christ", and intends to show that the life of faith is also susceptible to experience, is born in the sparking of an experience, the experience of having met Christ, and is transmitted through lived experiences, recognizable in the witness of the Church and of the believers. Besides the already mentioned Jean Mouroux (1901-1973), Romano Guardini (1885-1968) must be remembered as one of the most important 20th-century authors within this movement. The dimension of experience is also present in H.U. von Balthasar (1905-1988), whose thought is hardly reducible to other schools, but remains well founded on the credibility of love and on the ability of appeal that Revelation, along with its coherence and beauty, exercises on the aesthetic experience of the human being.

V. An Overall Synthesis

Even in light of its complex historical evolution, it would be incorrect to affirm that the notion of experience has basically changed through time. Indeed, the different perspectives considered here show that the various approaches to the same notion of experience were ways to search for solutions to different questions: the source of our practical, neither discursive nor reflective knowledge; the relationship of our knowledge with the reality of the external world or with that of our interiority; the absolute and necessary knowledge to which "rigorous science" aspires; the personal involvement, characteristic of our relationship with reality, also when the latter is intersected by the signs of the divine. Along the history of thought, different dimensions of experience were underlined or neglected, and others were simply not considered, having been taken for granted.

It does not seem necessary to offer any new "definition" of experience here, but simply to recognize its analogical character and to observe that any non-reductive approach will inevitably face a plurality of senses and typologies. At the same time, the different scientific, philosophical, and theological perspectives earlier underlined, as well as the inevitable plurality of theoretical contexts (empirical, psychological, metaphysical, methodological, critical, etc.), does not impede our sight turning towards certain fundamental characteristics of experience, and, therefore, towards the comprehension of its value within the epistemological discourse.

1. Understanding Experience: Some Common Characteristics. We will try here to summarize six characteristics which we maintain to be common to every experience: the personal dimension, the immediacy, the singularity, the general comprehension, being repeatable, and the objectivity.

Experience is always presented in a "personal dimension," lived directly by the subject itself, and therefore not shareable, at least in a strict sense: the experience of a physical event, of an intuition, of a pain, of a religious conversion, are necessarily confined to the subject; he or she can try to communicate its content, but through communication we lose its experiential character. In a strict sense, no subject can take part in the experience of somebody else; several persons can, at most, have contemporaneously the same experience of an external event, but each one will apprehend it in a personal way. This is true also for the religious experience, since to speak about a transmission of faith as communication of a living experience, means in reality to offer the conditions (listening to the word, witnessing, example, etc.) that may "reproduce in the other" the same experience possessed by the subject who intends to let the other participate in it. The second characteristic of every experience appears here clearly: its "immediacy." Experience is always possessed by someone in an immediate way, without having to look for mediation: experience presents itself as an existential data.

In its proper sense experience is always "experience of something singular and concrete"; there is no experience of the universal in a logical sense. Nevertheless, it implies also a certain "general comprehension", when considered as a source of practical knowledge, which will dispose the subject to act accordingly in new analogous cases (that comprehension, however, would not be a real "universal" knowledge, not being the result of an intellectual logical inference). Even when experience is understood as a method of confirmation of a hypothesis, it implies a previous generalization, even if the confirmation as such will continue to be strictly singular.

To be repeatable also belongs to the common discourse on experience. Such "repeatability," however, could result, at first sight, less significant when experience is seen in its personal and existential dimensions, especially if it is enriched by emotional values. These cases, which we could call "internal experience," seem to present themselves with a partial, if not total, lack of repeatability, having to do with the personal life of the subject. Yet, it would not be erroneous to recognize that, also in this case, we are facing an experience that can be, at least in principle, "repeated" by others; for example, as seen in regards to the transmission of faith, putting the other in the condition of having the same kind of experience. Daily life could offer numerous examples of our trust in this "being repeatable," when we want to include others in something which we retain existentially significant for ourselves. This suggests the idea that experience implicates always a certain "objectivity" of content, even in the case in which it concerns an internal or psychological knowledge. This does not mean to affirm its total objectivity, but simply allows for the conclusion that experience leads the subject to place himself or herself in front of something external (to oneself or to one's own cognitive act). This is the reason why experience is generally assumed as "data," as a starting point in the process of knowledge and of inter-subjective communication.

2. Experience as a Field of Dialogue between Theology and Scientific Thought. Some final reflections concern the dialogue between theology and scientific thought. Experience was seen for a long time as a discriminating element to affirm the objectivity and the universal communicability of scientific knowledge, in contrast with a body of subjective convictions as those transmitted by religious traditions. The different dimensions of experience recalled up to now, both in their epistemological and anthropological aspects, seem to be sufficient to point out the limits of such vision: scientific experience does not constitute a totally objective knowledge, nor can it separate itself from personal elements; religious experience, on the other side, admits canons of intelligibility and communicability which appeal to the objectivity of history and of every personal existence: in the case of Christian religion, this assumes, as we have seen, certain specific characteristics.

The recourse to experience reveals to be advantageous for the dialogue between sciences and theology also in another aspect. It concerns the attention that the theological work should give to such a category, with the aim of rendering its assertions more comprehensible even in the context of a scientific culture (cf. Blanco, 1996, pp. 52-54). Theological discourse, even when it has God as its object, starts from affirmations based on controllable experiences (a revealed word, salvific works, transmitted testimonies, etc.), whether individual or collective, historical and significant experiences which are therefore communicable. The theologian's attention to experience should regard not only the methodological rigor with which he or she evaluates and presents the questions belonging to the specific object of theology (God, Revelation), but also the care with which he or she welcomes and accepts the experiences coming from other sources of knowledge, being aware of the common objective basis (the truth about the human being and about the world) all these experiences participate in. A well-known text of Gaudium et spes makes an indirect but interesting reference to this capability of acknowledge the truth wherever it manifests itself, giving us the possibility to recognize it and experience it: "The experience of past ages, the progress of the sciences, and the treasures hidden in the various forms of human culture, by all of which the nature of man himself is more clearly revealed and new roads to truth are opened, these profit the Church, too. For from the beginning of her history she has learned to express the message of Christ with the help of the ideas and terminology of various philosophers, and has tried to clarify it with their wisdom, too. Her purpose has been to adapt the Gospel to the grasp of all as well as to the needs of the learned, insofar as such was appropriate. Indeed this accommodated preaching of the revealed word ought to remain the law of all evangelization" (n. 44).