You are here



I. Back to the Origin of the Experience and Concept of “Spirit” - II. The Spirit according to Judaeo-Christian Revelation. 1. The First Testament. 2. The New Testament. 3. Christian Theology of the Holy Spirit. - III. Philosophy and Modern Sciences. 1. From the beginning of the Modern Age to I. Kant. 2. German Idealism and its Developments. 3. Spiritualism and Positivism. 4. Contemporary Philosophies - IV. New Perspectives on the Dialogue among Theology, Philosophy and Science. 1. The Cosmological Perspective. 2. The Anthropological Perspective. 3. The Theological Perspective.

I. Back to the Origins of the Experience and Concept of “Spirit”

In the Western tradition —where the Christian and Hebrew revelations, as well as Greek-Hellenic philosophy, converge— the notion of “spirit,” or “mind” (Heb. rûah; Gr. pneûma; Lat. spiritus; Fr. esprit; Ger. Geist) is rich and complex for the various religious, philosophical and theological meanings it comprises. In this polysemantic horizon, the symbol/concept of spirit is inherently one of tension, if not even bipolar: from the theological point of view, it denotes the presence of God in relation to the world and, dialectically, His difference from it in terms of transcendence and sacredness/sanctity. In addition, it denotes personality (of God and men), and, at the same time, a certain kind of “supra-personality.” We can speak of the “Spirit of God / God as Spirit” to refer to this character of intimate tension —that quality of identity/relation and of transcendence/immanence— that, in Christian theology, takes shape and in some ways unfolds in the original figure of the Holy Spirit’s “Trinitarian Person.” From the philosophical and scientific point of view, this symbol/concept is at once, on the one hand, cosmological/anthropological and, on the other, typically theo-logical. It embodies, in an indissoluble correlation, the principle of the unity/totality of being and that of its multiplicity/multiformity. Indeed, in the history of thought, this notion took form especially in its dialectic relation with matter, where it progressively came to connote the incorporeal, invisible and elusive reality that, better than other definitions, could point to the vital (soul) and the inner dimension of human beings (intelligence and will, or even awareness), the nature of supernatural beings (angels and demons) and of God Himself, understood as what is absolute and transcendent compared to the natural world. Finally, this same relation has sometimes grounded the use of the word “spirit” to denote those substances (in the gaseous state) that, while belonging to the realm of materiality, differ from solids or liquids thanks to their thin and impalpable consistency, as well as to their capacity to easily and quickly dissolve in the environment. This is testified by the etymological origins of the word “spirit” (from Lat. spirare, to blow, to breathe) which makes it close to the term soul (that, in Sanskrit, corresponds to the terms atman or also áni-ti, which probably mean “He blows”). In this etymological origin we can sense the experience of that particular physiologic phenomenon that amazed primitive men at the time of a person’s death, when he/she exhaled his/her “last breath.” The connection to the image of the wind or of human breath underlined its material, albeit extremely thin and mobile, nature, whose figurative terms of comparison were represented by fire or air. The understanding of “spirit” as incorporeal reality has only slowly and gradually imposed itself in the history of Western thought.

As relates more specifically to Greek philosophy, Anaxagoras (ca. 500-428 B.C.) represents an isolated instance in pre-Socratic philosophy. His noûs (intellect) can also be translated as “spirit.” The pervasiveness and order it gives to all things, without being tied or confused with them, justifies the statement that each reality contains part of all other realities —the philosopher’s concept of perichoresis (see Diels-Kranz, B59, fr. 12) —, in the sense of a dynamic contemporary presence and interaction of natural parts which is performed by a spiritual principle that lives and acts in them. With the Stoics (Zeno, Cleanthes, Chrysippus, Poseidonius), the theory of pneûma gains the most accomplished meaning as a rarefied substance, able to move autonomously, a kind of thin fire (see. Plutarch, De stoicorum repugnantiis, 43, 1054), an animating blow that, as a vital element, moulds, permeates and orders universal matter (anima mundi), bestowing upon it a rational becoming through the logoi pneumatikoí — that is, the creating reasons, flickers of the creative principle that are contained in any corporeal reality. Each of these is also present, with the same properties, in every individual human being. It seems the word pneûma emerged in the medical field, where it was used to indicate the vital substance found in specific organs of the living body: the pneûma zotikón, located in the heart and the blood vessels, and the pneûma psychikón, placed in the brain and nerves, according to Erasistratus (a supporter of the strand of medicine called today “psychosomatic”); but also Galen’s pneûma physikón, which was in the liver. By analogy, the same idea was progressively extended to the whole universe, in the sense of a living organism animated by the pneûma as an eternal, material and rational principle, which produced the harmonic cohesiveness and connection of parts and ensured the unity of the whole. In men, this pneumatic element exists as the principle of their natural constitution and as a consubstantial part of the divine reality (cf. Seneca, Epistulae, 66, 12).

With Aristotle (384-322 B.C.), who followed Anaxagoras’ intuition, the notion of “spirit” acquires a more immaterial form, as an incorruptible and unextended substance. On the one hand, the human spirit is linked to perception through the senses while, on the other, it is autonomous in relation to the body, for it survives after death. Yet, for the Stagirite, the word pneûma indicates a substance that still has a kind of materiality, a middle ground between sôma (the body) and psyché (the soul). For Plato (427-347 B.C.), instead, it is the eye of the soul that allows us to seize the invisible. With time, the term came to identify an active and vital principle that was higher than animal and psychic components. In Neo-Pythagorean and Neo-Platonic thought, pneûma came progressively closer to psyche to indicate men’s superior activities: in this context, the tri-partite division of men into sôma, noûs and psyché (or pneûma) —already present in Stoic thought— is developed.

II. The Spirit according to the Judaeo-Christian Revelation

1. The Old Testament. In the Hebrew tradition, the rûah indicates an unpredictable breathing reality, whose dynamic is a source of life. In the First Testament this is the “breath” that gives life (cf. Gn 6:17; 7:15-22; Ez 37:10-14; etc.) to any living being, particularly men (cf. Gn 7:22; Nm 16:22; 27,16; Is 42:5; etc.), “breathing.” With this semantic connotation, it is linked to two other Semitic terms: nesamah (breath) and nefes (breath or soul). However, the unique and original experience of the people of Israel reveals the progressively conscious constitution of the relation of difference with Yahweh that established the covenant deriving from His free and incontestable offer. This relation constitutes the space in which the Spirit is experienced and understood; it is no longer conceived as a cosmic and all-permeating force, that is autonomous in itself, but as the “Spirit of Yahweh”, transmitted to human beings and to their world as the source of life and beauty. The rûah embodies God’s strength and creative fecundity (cf. Ps 104). This experience grounds its intrinsic connection to the promise; within the covenant in which the Spirit of Yahweh, embraced by human creatures, can act as a principle of liberation and justice, the presence/action of God in the history of His people and —in perspective— in the history of humankind as a whole takes place as a path marked by the irruption of the Spirit tending towards its eschatological effusion, as the condition of the advent of the full communication between God and His people and of liberating justice among men. This irruption manifests itself to and in the history of Israel through the gift of Yahweh’s word and power to the people He chose as proclaimers/mediators of the covenant and promise made to His People, Israel. In such a perspective the Spirit guides Moses, the Judges and the Kings (cf. Dt 34:9; Jds 6:34; 13:25; 14:6-9; 1Sm 10:10; 16:13-14), and it works as the source of inspiration and action in the Prophets (cf. Ez 2:2; 3:12-14; 11:5; Is 11:2; 42:1; 61:1); in this same perspective the figure of the “anointed” (Heb. masiah) stands out, whom the Spirit of Yahweh will “rest upon,” copiously, in order to make him able to “bring forth justice to the nations” (cf. Is 11:2-4; 42:1; 61:1). At the same time, this effusion will involve the entire people of the Covenant (cf. Ez chps. 36 and 37; Is 44:3; Zec 12:10; Jon 3:12); in fact, it will spread to the whole of creation. Moreover, in prophets such as Jeremiah and Ezekiel, Joel and Zechariah, the Spirit of Yahweh appears as the “new Spirit” placed “within” the heart of men (cf. Ez 36:24-28), the “creative transplant” of the redeeming will of communion and of liberation/justice of Yahweh in the very freedom of His creature. From now on, the Spirit will tend to be understood, as well as the space of relation/encounter between Yahweh and His people, as the inner principle, from God and —by his free concession— also from man, of the communion (between God and His creature) and of liberating justice (in social relations) (cf. Is 32:15-18). The literary figure of the personification of the Spirit, in the Wisdom writings (cf. Wis 7:22-23) —certainly under the influence of Hellenism that was contemporary to them— should also be interpreted as signaling the progressive understanding of the essential role of the Spirit, together with the Word, in the creative and redeeming work of Yahweh.

In an anthropologic-theological perspective, the rûah that derives from Yahweh goes back to Him when the living being dies (cf. Gn 2:7; Ps 104:29ff; Is 42:5; Ez 37:1-14; etc.); human beings live as long as “God’s breath” (Jb 27:3),  is in them; once this is withdrawn by Yahweh, men go back to dust (cf. Ps 104:29ff; 146:4; Eccl. 12:7; Jb 34:14ff). The notion of gift emerges here, which not only gives life, but renews it and transforms it by redeeming it from its condition of sin (cf. Ez 36:25-27). Therefore, the rûah should always be considered as a power of Yahweh, which causes created beings to be and acts on them, as God’s free will of relation with things created and especially with men; as the principle of communication, constitution and cohesion of the community. Moreover, the rûah characterizes feelings, thoughts and acts of will (cf. Ex 6:9; 35:21-29; Is 19:3; 26:9; 57:15; Ez 11:19; Mi 2:7; Ps 34:19; 51:12; Prv 14:17; 14:29; 21:2; 29:23; etc.). We can often find the opposition between the flesh and the spirit, between what is weak and precarious (in the human beings, see Is 40:5; Ps 56:5; 78:39) and what is strong and lasting (in God, see Hos 14:4; Jer 17:5-8), which can renew and redeem (cf. Ps 50). God is intended as He who owns and disposes of His enlivening spirit to the benefit of men and of the universe (see Gn 1:2), with no theory of His essence, even when aimed at a specific definition of the term “spirit.” In short, the rûah never denotes a reality that is autonomous and distinct from Yahweh: it is God Himself in His relation to the world and to the men He created.

2. The New Testament. Both in its self-awareness as transmitted by the Gospel writings, and in the interpretation offered by the apostolic tradition through the writings of the New Testament, the event of Jesus of Nazareth, on the one hand, stands in a relation of continuity with the actualization of the messianic promise and of the prophecy of the eschatological effusion of the Spirit; on the other hand it represents, in light of the Easter outcome of his mission (crucifixion/ resurrection), a groundbreaking difference also as relates to Israel’s experience/understanding of the Spirit. The messianic traits of Jesus’ mission emerge from the event of his baptism in the Jordan, interpreted as the calling and anointment in the Spirit, and presented as the key of interpretation of the Nazarene’s story as a whole; a similar function is held by the inauguration of Jesus’ mission in Nazareth’s synagogue (cf. Lk 4:16-20); hence the various expressions of this mission are all placed under the mark of the presence/action of Yahweh’s Spirit in and through Jesus. However, only some loghia of the synoptic Gospels state Jesus’ self-awareness (cf. Mt 18:28; Mk 3:28-29; Mk 13:11). Therefore, the presence/action of the Spirit in Jesus’ mission should be understood in light of his messianic choice, placed in the perspective of Isaiah’s Servant of the Lord, that is realized through the passion and the death on the cross, the path of obedience to God’s plan to spread the “Gospel to the poor,” as the event of the Kingdom that is justice-agape. In this perspective, the Spirit of God is that intimate push that guides and enlightens Jesus’ obedience towards the Father, the service and offer of His life to His fellowmen, which culminates in the death on the cross (cf. Heb 9:14; also Mt 1:18-20; Lk 1:35).

Starting from Jesus’ resurrection (cf. Acts ch. 2), the apostolic community experiences the “unlimited” effusion of the Spirit on “each flesh,” deriving from God Father through the Christ. This “first” experience of the Spirit, and ensuing understanding of His presence and identity, permeates Paul’s testimony of the life and faith of the first Christian communities. Therefore, in the New Testament, the Spirit can and must be called the Spirit of the Resurrected Christ, that is, the Spirit of that whom God has made “Christ and Lord” in the event of the resurrection; Jesus’ “coming” and His breathing on the disciples, on the eve of the first day after the Sabbath (cf. Jn 20:19-23), seems to follow the tale of the creation, of which it represents the intentional accomplishment. And the Spirit of the Resurrected One is that of the Crucified: this is confirmed both by the apostles’ reaffirmation of the undeniable centrality of the lógos toû stauroû as God’s dynamis and sophía (cf. 1Cor 2:4-5.10), and by Jesus’ “last breathing” on the cross (cf. Jn 19:30), the site and moment of “handing over” of the Spirit to men. The novum characterizing the Christian experience/understanding of the Spirit fully stands out here. The Spirit enacts the rightful relation between men and God and among men, thanks to, and in the form of, the relation lived by Jesus. That difference marked by the Christ-event and its Easter outcome acquires here a clearer delineation: the Spirit is of God the Father, as it descends from Him as His “quality” and, as such, it is conceded and transmitted to Jesus Christ, the Son; at the same time, the Spirit is of Jesus who, in turn, can freely return it to the Father and —in the resurrection— entrust it to men. In short, the Spirit is experienced as the divine reality of paternity and childhood that in some way exists between the Father and the Son, respectively actualizing the former’s paternity and the latter’s filiation —and their ensuing reciprocity— as an event of freedom/love.

The name “Holy Spirit” linguistically expresses the experience/understanding of the Spirit in Its own reality that should be distinguished from that of God/Abbà and of Jesus-Christ/Son, while being impossible to detach from them and targeted at the rightful relation between the Father and the Son and, within this, among men. Exegetes and theologians debate if, how and when, already in the New Testament, we can speak of a formally recognized “identity” of the Holy Spirit as distinct from the identities of the Father and of the Son. Beyond the trend of personification (already apparent in St. Paul: cf. 1Cor 2:10; 12:11; Gal 4:6; etc., and in St. Luke, especially in the Acts), which we can still interpret as a literary figure, it is especially the fourth gospel that presents the Holy Spirit as the Paraclete, the Other Sent by God (cf. Jn 15:26), after and through the incarnate, crucified and resurrected Son. The so-called “Paraclete discourses” —which constitute a decisive testimony for the subsequent dogmatic formulation by the Church— stress and in some way connect the three fundamental elements that embody the novum of the Holy Spirit’s identity as marked by the event of Christ. These three elements are: a) the personalization of the Spirit (the Paraclete), b) especially starting from the Easter event (cf. Jn 7:39 and 15:7), c) together with the definition of the reciprocal relations between the Father and the Son. The fourth gospel, in order to underline that the reality of the Paraclete Spirit has the same “nature” of the reality transmitted by the Father to the Son, inserts it in a dynamic relation of mutual glorification between Father and Son (cf. Jn 13:31-32; 17:5-24), which culminates in Easter and manifests the identity (“Only-Begotten” of the Father) of the Lógos-turned-flesh. Thanks to this mutual glorification, the Father and the Son are one in the other; in fact, they are “one” (cf. Jn 10:30; 14:8-10). All that the Father possesses He gives to the Son, thus “glorifying Him” —sharing His glory; and all that the Son receives from the Father is, in turn, “taken from” the Spirit and announced to men (cf. Jn 16,12-16). This same “glory” (Heb. kabod) seems to identify itself with the gift that is the Holy Spirit (cf. Jn 17:22-23), that which makes the Father “one” with the Son, albeit in their distinction; and, by being given by the Son, it is what makes the disciples “one” with Him and, through Him, with the Father.

3. Christian Theology of the Holy Spirit. In Christian theology some aspects appear fundamental to understand the identity of the Spirit. The dogmatic definition of the First Council of Constantinople (381 A.D.) —that, following the Council of Nicaea, denotes the Holy Spirit as the “Lord and Giver of Life” (DH 150), worthy of adoration and glorification as much as the Father and the Son— permitted to definitively overcome the uncertainty around the divine identity of the Holy Spirit. This uncertainty was typical of a firm trend in post-biblical Christian tradition that, in some cases, appears even regressive compared to the testimony of the New Testament; conversely, the Pneumatomachians, with a lectio facilior, essentially tended to bracket the threshold of difference represented by the NT. The experience of Christian salvation as witnessed by the Fathers certainly grounds the dogmatic affirmation of the equally divine nature of the Spirit (the omousía); if the action of the Spirit in us makes us experience God’s filiation in Jesus Christ, then the Spirit has to be God like the Father and the Son. Yet, on the one hand, the formulation based on categories of Greek-Hellenic philosophy; and, on the other —particularly in the Latin tradition— the restoration of the incarnate Son and of the Holy Spirit to the level of God the Father in the unity of the divine essence (the Trinity in itself), with time, have inevitably obscured the typically historical-redeeming and anthropological-social horizon in which the whole of biblical testimony is inserted. Beside the definite dogmatic affirmation of the personal identity of the Holy Spirit, a shadowing occurred of that economy of the Spirit that, actualizing the economy of the incarnate Word, is revealed/realized in the communication of freedom/justice from God Himself to men in their social relations.

In the Christian East, the centrality of contemplation and of liturgical action kept the original self-awareness alive, revived by the continuously renewed experience of the Spirit; yet, precisely this preference for the liturgical site will cause the East to miss the perception of the presence/action of the Spirit in the universe and in history. In the West, Joachim of Flores (1130 ca.-1202) represents a strong call, even if at times problematic, to a pneumatological theology of history. The very question of the Filioque (pneumatological question par excellence, even if today its relevance is greatly reduced: see The Declaration of the Pontifical Council for Promoting Christian Unity, The Procession of the Holy Spirit in Greek and Latin Traditions, September 8, 1995) is inserted precisely within this context, even if it favored the emergence of two different interpretations of the Christian event and, in the West, it strengthened the primacy of Christ-centered versus Spirit-centered interpretations. In this sense, the Filioque question favored the visible, institutional central and conceptually rational aspects, as opposed to the mysterious, communitarian, collegial and apophatically symbolic ones. Today, the complementary character of the two pneumatologic perspectives has been taken into consideration; they have been re-examined in a new light and in a broader horizon that highlight their profound richness as testimony of the New Testament and, in particular, the Trinitarian reciprocity embodied in the relations among the Father, the Son and the Spirit, based on the positioning of the Easter event of the Crucifixion/Resurrection as the specific key of interpretation.

III. Philosophy and Modern Sciences

1. From the beginning of the Modern Age to I. Kant. The Modern Age brings a new, radical understanding of the spirit and of its relationship to nature. The focus in thought shifts from worldly “givenness”—in its immediate appearance to knowledge— to the reflecting subject, the human being and his/her individual and communitarian world. In early modernity (besides physiological theories such as F. Bacon’s spiritus vitalis or R. Descartes’ esprits animaux) Descartes’ consideration of the spirit and matter as two separate and antithetical substances, will influence subsequent thought. The res cogitans, the thinking “spiritual substance,” opposed to the extension of matter, became the object of contestation and radical re-examination by Descartes’ successors. G.W. Leibniz (1646-1716) considers the spirit as the most elevated form taken on by the primary immaterial substance (monad) and as the quality that makes human beings distinct from animals, by allowing them to know the necessary and eternal truths, the rational soul (cf. Monadology, § 29). G. Berkeley (1685-1753), instead, using the terms mind, soul or my self (cf. Principles of Human Knowledge, I, § 2), affirms the substantive nature of the spirit as the only existing, simple, active, undivided reality of which we can only have a notion, but not an idea, through the operations of the mind. For David Hume (1711-1776), however, the transformation of the spiritual substance into a “collection” of ideas that he conceived favored, during the second half of the 18th century, naturalistic and materialistic notions of the spirit (J.-O. de La Mettrie, the Baron d’Holbach), which stood in contrast with those other interpretations of the spirit as the result of education and as the collection of new ideas (C.A. Helvétius), or those of the French philosophers and the supporters of occultism (E. Swedenborg). The identification of the “spirit” with notions such as conscience, mind, reason, intellect, soul, self, remained constant in subsequent periods. I. Newton (1642-1727) explicitly identifies the spirit with God as an all-powerful Being, the absolute subject, the primary cause that is present in the universe but, above all, as intelligence and will, able to observe and understand things in their depth (cf. Optiks, § 121), and to want their development, modification and transformation (cf. ibidem, § 145). It is, then, a “thinking substance” (ibidem, 509): it possesses a sensorium, the “infinite space” (cf. ibidem, § 121), a kind of “tool,” not divine, that allows us to penetrate, understand, move, configure and transform things down to their essential depths; in this way God makes nature His instrument.

With I. Kant (1724-1804), however, the very possibility of knowing reality, and the soul —which go beyond normal empirical apprehension— is questioned. The criticism of rational psychology will determine a shift in rational knowledge from the phenomenological to the noumenal domains (ethics and faith). In the Critique of Judgment, the philosopher of Königsberg uses the word “spirit” in order to denote, within aesthetics, what makes valid beautiful art, the “enlivening principle of the soul” (Critique of Judgment, § 49), the productive power and the originality of reason (cf. Anthropology, I, § 71), the capacity to show those ideas that can be adequately defined by no concept or thought in the products of imagination. The spirit is that dimension of experience that, as a resourceful and intuitive element, goes beyond the field of demonstrative reason and allows the ineffable to emerge without being constrained by pre-defined regulatory norms.

2. German Idealism and its Developments. Such an understanding will be taken as a theoretical premise by the whole of Romantic thought, which understands the dynamic of the spirit as creativity (see Idealism). The spirit, then, is the principle that gives concreteness to the form of the intellect. J.B. Fichte (1762-1814) identifies the spirit with productive imagination, that is, with the capacity to bring to awareness the most inner feeling, from which the highest ideas and inspirations derive. In Fichte, intellectual intuition is brought to the level of human most intimate and typical capacity, to their very essence. It is freedom, intended as a creative spontaneity able to set itself free from worldly constraints, the energy of thought opposed to any passiveness and slavery that derive from objective and material existence. The split between matter and spirit is also reproduced in J.C. Schiller (1759-1805), who laments the division between “physical men” and “spiritual men,” between the world of the senses and the world of form. Yet, Schiller considers the spiritual dimension as the site of synthesis of the material (concrete and particular) and intellectual (formal and universal) “impulses” and, at the same time, as the overcoming of these two dimensions in the absolute unity of reciprocal action. For G.W. Hegel (1770-1831) the Spirit (Geist) is the Absolute (cf. Encyclopedia of Philosophical Sciences, § 384), able to regain what belongs to it in the dispersion of exteriority, thus able to remain close to itself while becoming the other-from-itself. It is the Idea that, alienated in nature, returns to itself by acquiring self-awareness: the “subjective spirit” (the soul, or intellect, or reason) is only a moment that stands in opposition to the “objective spirit” (the State and other institutions of the human world: law, morality, ethics, culture and history). Both are surpassed by the “absolute spirit,” which manifests itself in philosophy, the form in which it is fully actualized as self-awareness, the overcoming of individual subjectivity in the self-awareness of a nation, a people, a human community, of the spirit in its universality. The “spirit,” then, is freedom (cf. ibidem, § 382), the “in oneself” that becomes other-than-oneself as a necessarily existing reality. These moments are taken and exceeded in the unity “that is in itself and for itself, and eternally produces itself: the spirit in its absolute truth” (ibidem, § 359). The spirit, that is posited as the “free will” (ibidem, § 481), “knows its own freedom and wants to be its object”: it is the “subjective spirit” (the soul, individuality) that must develop and surpass itself, getting to its own exterior objectivity and creating its own inter-subjective world in the juridical, moral, artistic, religious and scientific structures (the “objective spirit”). Finally, it finds its synthesis in the universality of conceptual knowledge, as self-awareness and total self-realization (“absolute spirit”). In Hegel and, through his influence, in all subsequent thought, this relation becomes an essential theme of philosophical reflection, precisely because it is intended as the fundamental element characterizing the life of the spirit and its possibility to be experienced. The attempt to take immanence within transcendence, finitude within infinity marks the intention to recuperate and make rationally explicit the religious dimension as the indissoluble link between divinity and humanity, which recalls the relational essence of the biblical spirit, through a new way of thinking (the “dialectic”) that understands negativity as the logical and real moment —which is unavoidable and permanent— of the very life of the spirit.

Hegel’s “philosophy of the spirit,” apex of the Western reflection on the spirit, left an indelible mark on all of 19th century and great part of 20th century thought. This is the case with Italian and Anglo-American idealism. In B. Croce (1866-1952), the Spirit is unity of thought and action in the distinction of the two fundamental forms or activities (theoretical or cognitive, and practical or volitional). Their totality is the goal of the Spirit, that is, it is the Spirit itself. This reality is articulated through four “distincts” (or categories, or “degrees”) that always implicate one another while always remaining distinct (aesthetic-intuitive degree or imagination; logical-intellectual degree or intellect; economic degree; ethical degree). This dimension and dynamic, which is the life of the Spirit, can be understood precisely and only by considering the “nexus of distincts.”. It consists precisely in this relation of unity-distinction, as the reciprocal implication-in-difference that characterizes reality. In G. Gentile’s (1875-1944) actualism, the Spirit is “pure act” that posits its object as multiplicity and re-absorbs it as a moment of its making; it is the “self-concept” that gathers all reality in itself, the thought that knows itself by actualizing as reality. The self-concept self-actualizes and self-knows in the three moments of the “pure subject,” “pure object” and of the Spirit as the unity or process of thought in which the (thinking) subject, and the (thought-of) object are necessarily present at once; the subject and the object are real only in the Spirit, which is the true reality of thought, beyond which nothing is real.

3. Spiritualism and Positivism. Another, parallel strand of thought, V. Cousin’s (1792-1867) spiritualism,” argues for a return to the spirit intended as individual consciousness and to its analysis in an attempt to derive, from the latter, the data necessary for philosophical and scientific enquiry; in so doing, this current of thought intends to recuperate traditional religious, moral, social and political values. More generally, this strand of thought, by showing great agreement with the Christian theological tradition, affirms the primacy of the spirit —intended in a personalist way, or as the spirituality of being— on matter. Its goal is a return to awareness in the Augustinian sense of inner reflection directed to identifying the elements necessary for theoretical activity. The spirit is considered as self-aware reality, present to itself, that human beings experience in the gnoseologic act of returning to themselves, to their interiority, in an itinerary that leads them to the Transcendent, to the finite spirits and the world. Spiritualism inspired Italian thinkers of the Risorgimento (Galuppi, Rosmini and Gioberti) and of the 20th century (Guzzo, Stefanini, Sciacca, Battaglia, etc.); it dominated the French philosophical scene (Maine de Biran and Renouvier in the 19th century, M. Blondel and E. Bergson in the 20th), as well as the German one (H. Lotze). The various spiritualistic trends imposed themselves, particularly in France and Italy, as a reaction to immanentist doctrines, to naturalism and scientism, expressing the need for a metaphysics alternative to prevailing materialism.

Indeed, positivism claimed for science to function as the guide and interpreter of human beings in all their expressions, both individual and collective (knowledge, ethics, arts, politics and religion). As the optimistic exaltation of experimental and exact sciences, positivism spurred and supported the emergence of the technical-industrial society, which would absorb and exhaust any inner (spiritual and religious) aspiration, with the claim to definitively solve any problem through a “positive” method (modeled after the hypothetical-deductive model of science), in view of a continuous progress of mankind towards its full realization. The application of this method to all thought domains entailed the abandonment of any metaphysical perspective and of any reference to the Transcendent, and the reduction of any dimension of reality to the set of material and mechanical forces that are inherent to any kind of being. According to this naturalistic current, every part of reality, by an intrinsic impulse, would spontaneously undergo a continuous evolutionary process, from the simplest to the most complex forms, independently of supernatural interventions.

4. Contemporary Philosophies. Positivist trends were also opposed by phenomenology, which E. Husserl (1859-1938) proposed as the “essential” and sense-based enquiry of reality carried out through an analysis of the Erlebnisse (experiences) of conscience. Against Positivism also stood the “Sciences of the Spirit,” a current of the second half of the 19th century, whose authoritative spokesman was W. Dilthey (1833-1911); this comprised all those disciplines that focused on the individual and collective expressions of the spirit. With Dilthey this field acquires specificity, by identifying those disciplines (history, economics, politics, religion, literature and poetry, figurative arts and music, systems of thought and psychology) that deal with men and human manifestations as inserted in history. According to Dilthey, what makes these disciplines different from natural sciences is precisely the quality of historicity that permeates any human action in the construction of the world. The task of philosophy, then, is to understand the different moments of history in and through which men have actualized themselves, and to describe the individual and collective relations that tie them to their own culture and social environment.

For existentialism too the spirit is that of Man, but intended as the freedom to express interiority that is unbound by the limits of exterior data (N. Berdjaev). K. Jaspers (1883-1969) considers the life of the spirit as the individual experience cast in a universal horizon of sense, an existential dimension that cannot be defined in a categorial way. The spirit, in order to defend itself from the chaotic and destructive trends of existence, produces forms to manage its own life; it continuously creates new forms not to be stifled by the preceding ones, which become rigid and lifeless. Hence the Philosophie de l’esprit, founded by L. La Senne and R. Lavelle with the aim to drastically oppose materialism, presents a positive view of the relation between the spirit and the world, where the latter is considered as the means and instrument of the former; in the world, reality gives itself to the spirit in order to be known and ordered and, at the same time, it constitutes the condition of freedom for the spirit itself. Through a phenomenological analysis of spiritual creations (arts, literature, sciences, technology, religion, philosophy, etc.), N. Hartmann (1882-1950) intends to demonstrate the objective nature of the spirit as “superstructure”, that is, its capacity to rise above psychic consciousness, and to be the real protagonist of history. Above the objective spirit stands the “living” spirit, intended as the union of the former with personal conscience.

The hermeneutic current that, since the Modern Age, has showed a profound connection with the theme of the spirit, deserves separate attention. In the theological-philosophical argument by F. Schleiermacher (1768-1834), the spirit takes on a fundamental role as the philosophical category at the very roots of the hermeneutical question. Because the Spirit is tied to the Word, the interpretation of the Word is operated in and through the Spirit, to the point that the hermeneutic act acquires a strongly “pneumatic” character. For Schleiermacher, however, the Spirit is in some way an immanentist interpretation of the theological notion of the Holy Spirit with a hermeneutic function, where it takes on the role of “universal mediator” in the process of interpretation, and sometimes acquires characteristics typical of the Hegelian Spirit. In the early 20th century philosophical context —after a period of oblivion due to the dominance of positivist doctrines— the theme of the spirit comes back in focus precisely within hermeneutics and the philosophy of language, also thanks to the contribution of theology —particularly with W. Pannenberg— and to the religious sensibility of some philosophers such as H.G. Gadamer, P. Ricoeur and F. Ebner.

IV. New Perspectives on the Dialogue among Theology, Philosophy and Science.

During the past few years speaking of the spirit has become the object of a complex and rich dialogue among the natural sciences, the philosophy of nature and theology. The concept of “spirit” —particularly the identity of the Spirit of God both in itself and in its relation to the world of nature and matter— has been dealt with by specialists in different religious confessions; these tried to answer the numerous speculative and “spiritual” questions posed by those theories that, as from the early 20th century, have drawn attention not only from the scientific community as, for example, was the case with Relativity theory and Quantum Mechanics. Ultimately, we are dealing here with the need for a reflection that spans a wider horizon and that, beyond the specialization and sectoring that characterize and divide the Western cultural panorama, is able to single out a dimension of meaning that embraces all domains of being, knowledge and action. When it goes so far as the study of elementary particles and of the physical foundations of reality, scientific inquiry itself can often lead researchers to pose questions on the depth of “being” and on the nature of spirituality in relation to their knowledge of the subject matter.

1. The Cosmological Perspective. In terms of the concept of “spirit” in relation to physics and cosmology, scientists propose different versions, albeit within the context of their own discipline and according to the philosophical-cultural and religious orientations they follow or are inspired from (Platonism and Pantheism, or Buddhism, Taoism, Hinduism or Christianity). Referring explicitly to the famous Platonic allegory of the cave, W. Heisenberg speaks of the spirit as the reality underlying any material appearance, sought by men as the truth, which we may call God in the Christian sense (cf. Physics and Philosophy, London 1959). The German physicist argues that the presence of immaterial principles, as already pointed out in Greek philosophy, is an objective fact —as are the facts of natural science— which manifests certain aspects of the world’s reality that are independent of time, hence they are eternal. The order of the spirit is then “central,” as it embodies the connection between the eternal dimension (of ideas) and the temporal dimension (of matter, to which belong the elementary particles that constitute original images, the ideas of matter itself; cf. Physics and Beyond, New York, 1971, pp. 215-216). For chemist I. Prigogine, who draws inspiration from the thought of H. Bergson, the totality of nature in its evolution can only be seized beyond partial descriptions, which are characteristic of science. The same applies to time, given its “spiritual” nature, a dimension that infinitely exceeds the capacity of understanding proper of scientific reason.

Within his explanation of nature, theoretical physicist P. Davies intends God as spirit (mind), that is, as a reality that permeates, enlivens and moves everything, thus giving it a project, meaning and goal. Davies stresses the absolute simplicity that characterizes infinite spirit and, at the same time, underlines that such a dimension is present only in systems with a certain degree of complexity. The existence and evolution of these degrees of complexity, particularly in living beings, reveals a finalism that brings us back to the action of a “mind” not just intended as the “author” of evolution itself, or as its ordering principle (cf. The Cosmic Blueprint, New York 1988; The Mind of God, London 1992). Each dimension of the spirit has a natural “dignity” that, for instance, surfaces in the dual relation between the body and the spirit, in analogy with the physical dualism of wave-particle or the information dualism hardware-software, similar to the Mind-Body Relationship. The physicist seems to relinquish the idea that, after death, the spirit is autonomously persistent, thus pointing to the necessity of the relation between spirit and matter for the existence of the former. Yet, Davies acknowledges the spirit’s autonomy endowed with creativity, following the model of the “scientific observer” (cf. W. Heisenberg, Physics and Philosophy, London 1959) that is placed at the same level as matter in a knowledge relation where the former dominates the latter. Such an “observing spirit” would cause the universe to be, among the many possible ones, even simply by perceiving it; in addition, by means of a “downward causation” (argument derived from Donald Campbell), it would also determine physical processes, as the higher ordering principle of matter’s self-organization, so that the whole of nature should be understood as its expression. Only “functions” (rational explanation of the world, endowment of meaning, planning and finalism) would belong to such a “natural divinity.”

According to F. Capra —in a parallelism between quantum theory and the various (mystical) oriental conceptions of the universe— the dualisms energy-matter, space-time, waves-corpuscles constitute a unity in which we can recognize the “spiritual world of non-distinction” (cf. The Tao of Physics. An Exploration of the Parallels between Modern Physics and Eastern Mysticism, 1975). Yet, the spirit is the principle and process of self-organization, which identifies itself with life, that is, God. This self-organization is called “Trinitarian” precisely because it permits the association of the idea of “process” with that of the Spirit, that of “structure” with the Word incarnate and that of the “blueprint” of organization with that of the Father. Drawing from the Indian myth of the “God that sacrifices Himself,” Capra understands God’s becoming as the world and, in turn, the becoming of the world as God. In the “self-organization” of matter (particularly of animate matter), proposed by astrophysicist E. Jantsch, chaos and order are complementary, as the dynamic that engenders life and continuously renews itself. At the basis of this life, able to transform the universe according to its goals, are the laws of nature that transcend other laws, replace them and correct them, within a movement endowed with self-control. Underlying this world vision is the faith in an immanent divinity that is not the Creator, but the “spirit of the universe” (cf. Die Selbstorganisation des Universum, München 1992, pp. 412-415), the Self of the universe of living beings that underpins that process of self-organization, thus guaranteeing its invincibility based on its divine power.

2. The Anthropological Perspective. The anthropological perspective raised particular questions concerning the relation between the animal and the spiritual elements. According to “monistic” arguments, both animate matter and the spirit in its various dimensions are brought back to one only reality that makes them similar (think, for example, of today’s “theory of identity”: the spirit would be a function of the brain given that, at a certain degree of organization of matter, moods and conditions of consciousness would be in the neurons). According to “dualistic” explanations, typical of Platonic thought —formulated, among others, by chemist H. Sachsse and by physicist H. von Ditfurth— the spirit, a reality completely “other” and superior to matter, would constitute the latter’s principle of organization and characterization. Today, a version of this theory, called “interactionism,” would operate a clear distinction between the “spirit” (mind) and the brain (or body) so that, while related, the spiritual element would not be reduced to the neuronal functions of the central nervous system and of the brain. Through an accurate knowledge of the cerebral structure and its corresponding functions, S.N. Bosshard states the need to put aside the various forms of reductionism in order to embrace the “paradox of unity and of the distinction of the two figures of reality” (Erschafft die Welt sich selbst?, Freiburg 1985, p. 78). Two examples such as J.C. Eccles’ theory of interaction and R.W. Sperry’s emergent interactionism differently argue for an interaction of the spirit with the neuro-cerebral system, while keeping the two dimensions distinct, based on the non-reducible and peculiar nature of the spiritual element; in this sense, the brain would be an actual “organ” of the spirit.

3. The Theological Perspective. Within Christianity —starting from the innovations undergone by all traditions (Catholic, Orthodox, Reformed) as from the first decades of the 20th century— we can find several attempts to reinterpret the question of the relation between God and the world, the spirit and matter, human beings and the universe, in a comprehensive horizon that is closer to the Christian revelation, able to overcome the dualisms of spiritualism and materialism, without yet falling into forms of immanentism and pantheism. In this sense, the world visions formulated by the Russian religious thinkers of the so-called “silver age” —V. Solovie’ëv, P. Florenskij, S. Bulgakov— are pioneering. These thinkers perceive the urgency of a Christian cosmology and stress —in line with the liturgical-sacramental Orthodox tradition— how the gaze of the Christian looking at and interpreting the world is the gaze of the disciples on Mount Tabor, where the flesh of Christ, synthesis of the materiality of the universe, is transfigured by means of divine energy. We should then overcome the modern Western separation between spirit and matter and the prejudice that nature is separate from the spiritual dimension of human life and from God’s presence in the world. S. Bulgakov (1946), for example, writes: “Not only is the spirit not opposed to matter; it identifies with it in the form of energy: it is its strength. […] this spiritual character of the creature’s substance, which is determined by the latter’s positive relation with the spirit, can have different modes and degrees […] the spirit never stands in opposition to the animal and bodily life of human beings, but lives in it, by determining it and, in turn, by being determined by it” (Le Paraclet [Paris: Aubier, 1946], pp. 330-331). In catholic theology we should recall, in the same perspective, Teilhard de Chardin’s well-known cosmovisions and K. Rahner’s symbolic interpretation of the relation between spirit and body.

More recently, some contemporary theologians have proposed a reading of the latest scientific hypotheses and discoveries in light of the New Testament revelation and of the ensuing ecclesial experience, based on the conviction that a dialogue between theology and natural sciences could benefit both, in terms of the meaning of scientific research and results, as well as in terms of a greater understanding of the reality of God and of human beings.

Referring to nature, J. Moltmann (1993) states that “we give the name of spirit to the forms of organization and modes of communication in ‘open systems.’ We can begin with informed matter, move up through the forms of living systems, the many strata of living symbioses, human beings and human populations, and end with the ecosystem ‘earth’, the solar system, our Milky Way galaxy and the whole complex of galaxies in the universe” (p. 17). At each of these levels, the organizing principles of the Spirit are “self-affirmation” and “integration” —as relates to the synchronic dimension— and “self-preservation” and “self-transcendence” —as relates to the diachronic dimension. The Spirit tends to merge open life systems into symbiotic life forms and to develop ever richer forms of life in the field of possibility, the future. On this basis, Moltmann considers “Spirit” as synonym with self-organization and self-transcendence, with inner and outer symbiosis (cf. ibidem, p. 18), with the comprehensive principle of organization, so that the human spirit is related to the bodily-psychic structure as a whole. In the Spirit every man is socially and culturally joined to other human beings, in a bond that is an openly organized system (spirit common to human collectivity). Through the Spirit every man is joined to the natural environment (psychic ecosystem) and each human society is connected, like sectoral systems, to the ecosystem “Earth” (cosmic spirit). According to the German theologian, then, it is necessary to extend the “human consciousness of the Spirit” to as many possible formations of the Spirit itself, and to dilate it, according to the principles of organization, towards social, ecological, cosmic and divine consciousness, so that it reaches higher, more complex and stratified organizational forms, in order to attain a superior and differentiated vital exchange. The Spirit, moreover, is the “principle of creativity” at all levels of matter and life, it creates and anticipates new possibilities and schemes; through the concept of “self-movement” it can be understood as the “principle of evolution.” It is the “holistic principle” because, at each stage of development, it creates reciprocal interactions, harmonies and perichoresis (communitarian life of the divine Persons as One-within-the-Other); it is the “principle of characterization and differentiation” of material and vital forms at different levels of complexity; it represents the “principle of intentionality” in the sense that it directs all creatures towards a common future, that is intrinsic to and peculiar in each of them according to specific features and possibilities (cf. ibidem, pp. 100-101). For Moltmann, human consciousness is a reflecting and reflected spirit (cf. ibidem, p. 18), it is awareness of the organization of its life, its interiority and of the relations that are necessary to human organisms in order to live in nature and in society. The body and the soul are permeated, enlivened and characterized by the “Creative Spirit,” so that human beings are “spirit-body” and “spirit-soul” and, at the same time, a unity characterized by the Creative Spirit (here intended as cosmic spirit); human beings, therefore, are “spirit-figures” that only exist in the natural and social exchange with other living beings. Yet, from the theological point of view, the Creative Spirit, the Spirit and Presence of God in His creature, is not the Holy Spirit (cf. ibidem, p. 263), intended as the Spirit of redemption and sanctification, the Spirit of Christ, the presence of God that redeems, re-creates, envelops the totality of human beings thus making them similar to Christ (cf. Phil 2:6) and inserting them in the community of believers.

In W. Pannenberg’s interpretation of the relationship God-world, the analysis of the biblical testimony reveals the Spirit of God as the principle that gives life, movement and activity to all creatures. It is the divine breath that is directly breathed in them and that stirs primeval waters; it is not only an event that occurs in God’s interiority; “God’s breathing is a ranging storm, and from its dynamic issues the creative speaking” (Systematic Theology, [Edinburgh: T&T Clark, 1994], vol. 2, p. 79). If the ultimate goal of physics is to describe the forms of movement and moving forces, then, precisely in the recent hypotheses that try to explain such phenomena we can identify a hermeneutic relevance that is implicitly theological. In particular, according to Pannenberg, the theories of the “fields of force,” which developed starting with M. Faraday, seemingly reveal some degree of compatibility with the Christian understanding of the dynamic activity of the divine pneûma in all created things. According to Faraday, bodies would be the expression of forces, intended as autonomous realities preceding physical phenomena, which can be represented as “space fillers,” as the totality of a field that envelops one or several bodies. The mass would depend on the concentration of forces in different points of space, and matter particles would be the point in which lines of force converge, or a cluster of such lines with determinate duration.

Biblical statements on the Spirit of God / God as Spirit would suggest, according to Pannenberg, an interpretation of the “field of force” as structured in a Trinitarian way, where the Person of the Spirit must be understood as one of the personal actualizations of the only God Spirit, that is, in relation to the Father and the Son. In this perspective, the Person of the Holy Spirit would be a single manifestation (singularity) of the field of divine essence and, because its being-person only manifests itself in the relation to the Father and to the Son, its action in creation would be characterized as the dynamic field effects, that is, the capacity of relation —albeit with differences— with the intra-trinitarian dynamic, which are due to the time conditions that characterize the spatial conditions of creatures, in which it must insert itself and act by overcoming them (cf. ibidem, pp. 82-84). The dynamism of the Holy Spirit should indeed be understood as an operative field that is influenced by time and space. It dilates in time, through the power of the future —the site of possibility of events and of the eschatological accomplishment of God’s Kingdom, already present in Jesus Christ— that endows each creature with a present and a duration; it also dilates in space, which guarantees stability to creatures in their simultaneity (cf. ibidem, p. 102).

To sum up these considerations, I believe that beyond the varied philosophical-theological experiences and reflections on the Spirit in the history of thought, and beyond the changing personality with which it has been taken as an object of conceptualization or mere representation, its presence and action in what belongs to the deepest nature of humanity is recognized; it has also been acknowledged as something that is implicated by the world’s nature and logic. For their part, the natural sciences do not recognize the spirit as a proper object of their method; yet, they signal all the same the reasonableness of those that refer to it in the understanding of nature and its phenomenology, especially life, thus recognizing the interpretative limits of both reductionism and materialism. Revelation offers its specific contribution to philosophical thought and science, stressing in the Spirit the reason of a gift, a presence and a promise that, from the beginning, has intended to accompany and guide the project of the One Triune God for creation and salvation.

Documents of the Catholic Church related to the subject: 

Abbreviations and complete titles of the documents

Council of Constantinople, DH 150; Synod of Sens, DH 722; Leo XIII, Divinum illud munus, 9.5.1897; Pius XII, Mystici corporis, DH 3807-3808; Gaudium et spes, 11, 26; John Paul II, Dominum et vivificantem; John Paul II, General Audiences, from 26.4.1989 to 20.12.1989, 19.8.1998 and 2.8.2000.


Philosophical Works: H. BERGSON, Creative Evolution (1907) (Mineola: Dover Publications, 1998); H. BERGSON, Mind-Energy: Lectures and Essays, transl. by H. W. Carr (Westport: Greenwood Press Reprint, 1975); W. DILTHEY, The Critique of Historical Reason (Chicago: University of Chicago Press, 1978); P. FLORENSKIJ, Smysl idealizma (Sergiev Posad, 1914); G. GENTILE, Teoria generale dello spirito come atto puro (Firenze: Sansoni, 1938); G.W.F. HEGEL, Phenomenology of Spirit (1807) (Cambridge (MA): Oxford University Press, 1979); G.W.F. HEGEL, Encyclopedia of the Philosophical Sciences (18303), ed. by Ernst Behler (New York - London: Continuum, 1991); J. MARITAIN Quatre essais sur l'esprit dans sa condition charnelle (1939) (Paris: Alsatia, 1956); M. SCHELER, Man's Place in Nature (New York: Farrar Straus & Giroux, 1962); P. TEILHARD DE CHARDIN, The Divine Milieu (1957) (New York: Harper Perennial, 1975); P. TEILHARD DE CHARDIN The Phenomenon of Man (1955) (New York: Harper Perennial, 1976).

Theological Aspects: R. ALBERTZ, C. WESTERMANN, rûah (Spirit), in TLOT, vol. II, pp. 1202-1220; S. BULGAKOV, Le Paraclet (Paris: Aubier-Montaigne 1946); Y. CONGAR, I Believe in The Holy Spirit (New York: Crossroad - Herder, 1997); G. FERRARO, Lo Spirito e Cristo nel Quarto Vangelo (Brescia; Paideia, 1984); H. KLEINKNECHT ET AL., “Pneûma”, in TDNT, vol. VI, pp. 332-455; F. LAMBIASI, Lo Spirito Santo: mistero e presenza. Per una sintesi di pneumatologia (Bologna: EDB, 1991); F. LAMBIASI, “Holy Spirit”, in DFT, 1994, pp. 455-462; R. LAVATORI, Lo Spirito Santo dono del Padre e del Figlio. Ricerca sull'identità dello Spirito come dono (Bologna: EDB, 19982); J. MOLTMANN, God in Creation. A New Theology of Creation and the Spirit of God (Minneapolis (MN): Fortress Press, 1993); J. MOLTMANN, The Spirit of Life. A Universal Affirmation (Minneapolis: Fortress Press, 2001); R. PENNA, Lo Spirito di Cristo (Brescia: Paideia, 1976); R. PENNA, Spirito Santo, in NDTB, 1988, pp. 1498-1518; H.U. VON BALTHASAR, Spiritus creator. Skizzen zur Theologie, III, (Einsiedeln: Johannes-Verlag, 1967); H.U. VON BALTHASAR, Explorations in Theology: Spirit and Institution (San Francisco; Ignatius Press, 1995); H.U. VON BALTHASAR, Theo-Logic: Theological Logical Theory; The Spirit of Truth (Theo-Logic) (San Francisco: Ignatius Press, 2005).

Dialogue between Theology, Philosophy and Science: M. BARTHELEMY-MADAULE, Bergson et Teilhard de Chardin (Paris: Ed. du Seuil, 1960); F. CAPRA, The Tao of Physics. An Exploration of the Parallels between Modern Physics and Eastern Mysticism (1975) (Boston: Shambhala, 2000); M. CINI, Un paradiso perduto. Dall'universo delle leggi naturali al mondo dei processi evolutivi (Milano: Feltrinelli, 1994); P. DAVIES, The Cosmic Blueprint (New York: Simon & Schuster, 1988); P. DAVIES (ed.), The New Physics (Cambridge: Cambridge Univ. Press, 1989); P.C. DAVIES, The Mind of God. Science and the Search for Ultimate Meaning (London: Simon & Schuster, 1992); A. EINSTEIN, The World as I see it (London: J. Lane, 1955); A. GANOCZY, Suche nach Gott auf den Wegen der Natur (Düsseldorf: Patmos, 1992); W. HEISENBERG, Physics and Philosophy. The Revolution in Modern Science (1958), introd. by P. Davies (London: Penguin, 1990); W. HEISENBERG, Physics and Beyond (New York: Harper & Row, 1971); J.C. ECCLES, D. ROBINSON, The Wonder of Being Human (London - New York: Macmillan - Free Press, 1984); I. PRIGOGINE, From Being to Becoming. Time and Complexity in the Physical Sciences (San Francisco: W. H. Freeman, 1980); J.C. POLKINGHORNE, Belief in God in an Age of Science (New Haven: Yale Univ. Press, 1998); K.R. POPPER, J.C. ECCLES, The Self and its Brain. An Argument for Interactionism, 3 vols. (Berlin - Heidelberg: Springer, 1977); J.R. SEARLE, The Rediscovery of the Mind (Cambridge (MA) - London: MIT Press, 1992); J. SEARLE, The Mystery of Consciousness (New York: New York Review of Books 1997); R.W. SPERRY Science and Moral Priority. Merging Brain, Mind and Human Values (Oxford: Blackwell, 1992).