In its root meaning, the word "existence" stands for presence or being present, the affirmation, manifestation, or appearance of something in any category, whether this be in nature, where it is known as material existence, or in mind, where it is known as ideal existence.
Notion of existence. Existence thus signifies the fact that something is present in nature or in mind, and this in a precise spatiotemporal way. It therefore preeminently asserts reality in act and points to being as the exercise or actualization of reality of any kind. As such, existence is primarily distinguished from and opposed to nonbeing or nothing; only secondarily is it distinguished from the possible (see possibility). The possible differs from nothing in that nothing cannot be conceptualized and resists passage into being, whereas the possible can be conceptualized by mind and thus pass into being. Yet when the possible does not de facto pass into being, it has no existence in reality, that is, no existence in the full, true, and proper sense. Existence thus includes a content and is thereby related to essence. It is, in fact, the actualization of essence, its de facto placement (existere ) in reality, since essence was possible before being actualized. One may say that essence exists in reality to the extent that it has passed from the sphere of possibility to that of actuality. Since it does not do this by its own power— otherwise possibility would become identical with reality—but through an external principle or cause, such existence implies the agency of some causal principle.
The affirmation of existence can be extended to formal logic and there signifies the attribution of a predicate to a subject. Similarly in the field of mathematics, one speaks of the existence of irrational numbers and of n -dimensional space, to the extent that such entities or postulates are logically consistent and imply consequents of use in the mathematical sciences.
Intentional levels of existence. The idea of existence, like that of reality in general, can be located on various intentional levels and distinguished according to its proper content at each level. One can thus speak of experimental existence, which is immediately sensible, and of existence that is imagined or fictive, ideal, logical, artistic, moral, legal and so on, depending on the intentional medium used to represent a particular reality.
Primary Experience of Existence. Existence in its full, proper, and primary sense is that which is affirmed by immediate sensible and mental experience, whether this be direct or indirect and whether it come from experience that is external (objective existence) or from that which is internal (subjective existence). Such existence presents itself to thought in an immediate manifestation. It is in this sense that Aristotle claims it would be ridiculous to try to show the existence of nature (Phys. 193a3) and that St. Thomas Aquinas advances the fact of self-perception against the Averroists (De unit. intell. 3). The de facto existence of external experience, for example, of the books on the table where I write or of the street I see from the window, is primary and is in a certain sense the foundation for the existence of internal experience (St. Thomas, In 3 sent. 23.1.2). But even the existence of internal experience is immediate; it is made evident in reflective awareness of life and activity on the part of the knowing subject. Its focus is the existence of the acts and functions of the subject's perception and of states of his soul, to the extent that these deal with the instinctive and reflective life of the individual (ibid. ad 3).
Existence of Soul and Its Faculties. Concomitantly and by implication, the individual comes to an awareness, though indirect and conditioned by his experience, of the proximate principles that produce his knowing acts. These are his powers or faculties, namely, (1) the sense faculties, recognized through sense experience, (2) the intellect, known in the act of understanding, and (3) the will, known in the act of volition (De malo 6.1 ad 18). The circle of existential experience, extending all the way to the intellect, is integrated in the unity of the soul's essence (In 3 sent. 23.1.2 ad 3). The presence or perception of the existence of these acts and potencies implies the presence of, and thus a profoundly basic insight into, the existence of the soul as a first principle, as well as some knowledge of its nature (De ver. 10.8 ad 8 in contrarium ).
Existence of Privations. Privations are indirectly yet immediately perceived; these include all evils, whether of the physical order (bodily pains, sickness) or of the moral order (the malice of an act, of a bad habit or vice). Although not "real" in the strict sense, privations can be said to have existence without a proper essence, inasmuch as they are not "something," but merely indicate the fact of lack or absence in an apt subject. (see privation.)
It should be noted that the various perceptions of existence and the activities that produce them are complementary. In fact, when the structure of the object is disturbed, the subject loses the perception of the existence of the ego itself, and experience runs wild as in a dream world where there is no distinction between appearance and reality.
Mediate Knowledge of Existence. When knowledge of existence does not result from perception but from demonstration, it is referred to as mediate knowledge of existence. This applies to realities that are not or cannot be immediately present to the knowing subject, either because they are distant (in space) or absent (in time), or because their mode of existence transcends space and time, as for example, spiritual substances and God. Mediate knowledge of the existence of things distant or absent can result from various kinds of demonstration, depending on the type of knowledge proper to such objects, for example, experimentation, physico-mathematical demonstration, and scientific construction. Such demonstration can also convey an immediacy of experience, as seen, for example, in the physical and biological sciences. On the other hand, knowledge of the existence of superior or transcendent beings, for example, God, remains always and solely mediate knowledge, that is, knowledge achieved through demonstration. The starting point is the existence of created things precisely as these reveal themselves as effects of divine omnipotence, and the demonstration itself invokes the principle of causality (St. Thomas, Summa Theologiae 1a, 2.1–3). Even so-called religious conversion and mystical experience cannot, strictly speaking, provide an immediate perception of the existence of God or of His attributes, but only that of particular effects associated with the spiritual life and its development.
Existence of the Supernatural. The only certain experience of the existence of the supernatural is the experience of the act of faith. In fact, without a special divine revelation no one can be certain of being in grace, but can only have conjectural knowledge of this (ibid. 1a2ae, 112.5). But everyone can, and should, have certainty of the existence of faith. Even though supernatural faith depends on a divine influx, it does require an act of man's intellect and will, and he himself can have a direct knowledge of this from both an objective and a subjective standpoint (ibid. 1a2ae, 112.5 ad 2; 2a2ae, 2.1 ad 3). The explanation for this lies in the fact that while the intellect is the foundation of man's unity of perception and thus can know both the existence and the nature of all the potencies that are actualized, including acts of the will, the will establishes in man a unity of action (ibid. 1a, 82.4 ad 1). For this reason, as S. A. Kierkegaard proved against G. E. lessing and modern philosophers, the Christian's act of faith constitutes the decisive proof and the surest commitment the human person can have for God.
Formal Existence. In the abstract areas of logic, mathematics, art, morality, and the formal sciences in general, existence is not considered as an extramental and extrasubjective datum and fact. Thus it does not have the same connotation as existence in the strict sense as this is applied to factual reality.
HISTORY OF THE CONCEPT OF EXISTENCE
It is to Aristotle's credit that he distinguished with semantic rigor the problem of existence from that of essence (τò ὅτι τò διότι). For him, the first is related to the external causes, efficient and final, whereas the second is related to the intrinsic causes, matter and form (Anal. post. 78a 22–79a 16; Meta. 1041a 15–1041b 33).
Greek thought. In the terminology of aristotle, existence has two modes of being, potential and actual, since the plant exists in "some way" in the seed even before generation, as does the animal in the egg (Meta. 1046a 10–36). Yet for Aristotelian thought, which rises above the myth of origins and does not recognize the problem of creation, existence has no meaning in itself. Being means always and only an essence as actualized; spiritual and incorruptible essences are always actual, while material essences pass from potency to act in the ternal cycle of generation and corruption (cf. Gen. et cor. 335b 4). On the other hand, since ideas or pure forms do not exist in themselves, temporal existence is the only reality proper to material essences; to speak about the existence of "separate Ideas" is "to use empty words and poetical metaphors" (Meta. 1079b 26). For this reason, and because the world was viewed as eternal and matter as uncreated, Greek thought gave maximum significance to existence as the unique form for real being. In such a context, God Himself exists to the extent that His essence is an act like the property of an essence, or as a pure act of understanding; this distinguishes Him from other substances and forms (Meta. 1072b 25; 1074b 33).
For parmenides, as opposed to Aristotle, existence is the presence of varied sensations gathered into a unity, into the truth of being that is the act of the intellect; likewise for heraclitus, the unity and truth of existing things is guaranteed by the logos. Both, therefore, affirm the truth of existence through the agency of the intellect. This truth of being, the pinnacle of Greek thought, was materialized by the Stoics when they identified the λόγος with the π[symbol omitted]ρ τεχνικόν or πνε[symbol omitted]μα diffused through nature; thus the development of existence was entailed in the necessary evolution of the destiny (εἰμαρμένη) of the All.
A similar process, but in a direction opposite to that of the Stoics, was the Neoplatonic concept of creation. In the thought of plotinus, there is an emanation of the three primary Hypostases from the overflowing of the One according to the principle that each Thing complete in itself tends to reproduce itself (Enneads 5.1.6). According to proclus, this takes the form of a procession that repeats and produces the hierarchy of formal values in the real order of participation (Elements of Theology, prop. 25–39). Thus, at the close of Greek philosophy, existence is reabsorbed into essence, real causality into formal derivation, and the πρ[symbol omitted]γμα into the λόγος.
Early Christian conceptions. The passage from the classical to the Christian concept of existence is marked especially by the knowledge of total creation through the free agency of divine will (Gn 1.1). Created existence is thus given an absolute and total dependence on God, and God's role in creation is conceived as a historical intervention, a real relation of temporal reality to the freedom of the divine will. Divine life in this way became transcendent and clearly above involvement in the world. Granting creation, the existence of the world is a contingent fact—as far as God is concerned, because He need not have created it; as far as the world is concerned, because its existence remains always dependent on a continuation of the divine influx (St. Gregory, Moral. 16.37; Patrologia Latina, 217 v. [Paris 1878–90] 75: 1143).
Thus a new aspect was seen in the concept of existence apart from its dependence on essence: the essence of things is related, according to the exemplarism of St. augustine and of pseudo-dionysius, to the knowledge of God, that is, to the divine intellect insofar as this conceives in itself the forms of the things it creates.
Arabian philosophy. Thus the Christian concept attributed the greatest possible concreteness to existence. On the other hand, arabian philosophy, faithful to the Neoplatonic concept of creation as necessary emanation through successive levels, denied God's direct knowledge of, and therefore providence over, the singulars that are the true existents. Yet in the thought of al-fĀrĀbi and avicenna, closer to the theology of the kalĀm, God was conceived as necessary existence and the creature as possible existence. From this followed the basic contingency of existence when cut off completely from essence, so that existence came to be identified with divine causality sustaining the created world (see causality, divine).
In Arabian philosophy, existence, as an existential affirmation corresponding to the τò ε[symbol omitted]ναι and to the ὅτι of Aristotle, is indicated by the word annīyya (the anitas of the Latin versions). This can also indicate the concrete existent that is the individual, as well as the subsisting archetypal idea. The Arabs could therefore distinguish essence (mahīya ), existence as actualization of the essence (huwīya ), existence as actuality or realized essence (wugud ), and finally existence as fact and realization of fact (annīyya ).
Scholasticism. At the beginning of the thirteenth century, the schoolmen followed for the most part the direction of Avicenna and reduced existence to a "relationship of dependence" of the creature on God. This formulation appears most clearly in robert grosseteste (In 2 anal. post. 1.1). It received almost universal acceptance until recent times, although directly opposed to the Thomistic concept, which is treated fully below. Its chief promoter, henry of ghent, introduced a new terminology; discussing the structure of the finite, he distinguished a twofold esse, an esse essentiae, and an esse actualis existentiae (Quodl. 1.9). Thus existence, for him, indicated the simple fact of being or, rather, the passage of an essence from possibility to actuality; but since the creature remains ever dependent on divine causality, existence retained also an accidental connotation based on extrinsic participation.
Modern philosophers. This development was jeopardized by modern philosophers, who reduced the "moment of existence" to the sphere of phenomena, that is, to immediate sense experience or so-called empirical reality. The significance of methodical doubt from R. descartes to D. hume, I. kant, and G. W. F. hegel, was hat it considered as nonreality the whole realm of immediacy that was suppressed by making a new start with the cogito.
In Spinoza's monism, single existents are finite realities, united in the one Substance while themselves remaining multiple and transitory. B. spinoza reasserted the scholastic concept of existence under its formal aspect, but without its theological basis, and thus introduced a new rationalist concept of existence. His metaphysical "indifference," assigning existence to the realm of the irrational, was accepted by G. W. leibniz through the principle of sufficient reason, implied both by the creation of this world as the best possible and by the appearance within it of single, real existents. C. wolff attempted a further clarification in terms of the realistic principles of the scholastic tradition. Defining existence in the Leibnizian manner as complementum possibilitatis, he explains that such completion signifies, in natural theology, dependence on God; in cosmology, the order of contingent things in the material world; and in psychology, the activity of the human mind in conceiving its thoughts.
In his precritical period, Kant found this definition to be too vague, as he did those of A. G. Baumgarten (existence is "complete inner determination") and those of C. A. Crusius (who reduced this to spatiotemporal determination), for failing to explain why existence is distinguished from possibility. Kant, therefore, inverted the order: for him, possibility presupposes and bases itself upon existence. Returning then to the Avicennianscholastic concept that existence cannot be deduced from essence, Kant in the critical writings conceives existence as an a priori category of the mind, a second instance of the modality opposed to nonbeing and situated between possibility-impossibility and necessity-contingency. Thus existence was related to space and time, as in Crusius's exposition, with the difference that the relation was a priori or transcendental (Critique of Pure Reason A 80, B 105). Unlike Hume, for whom existence, like substance and causality, is a subjective operation, or "idea," of the imagination derived from experience, Kant relates existence to the operation of the pure intellect as a category.
For existence Kant uses the two terms Dasein and Existenz almost indifferently; these acquire clearer distinction in the Hegelian dialectic. Dasein is the instance of empirical immediacy and multiplicity, and thus of non-truth, of the pure presentation of phenomena as leading to the mediation and to which pure being corresponds as identical to nonbeing; Existenz, on the other hand, indicates the instance of what Hegel calls "second immediacy" or "reflected immediacy" or "simple essential immediacy," which follows upon the mediation of essence and therefore explains the dialectical identity of contraries in action. Existenz may be called the instance of externality based on essence (Wesen ), which is the moment of the underlying interiority, and their synthesis is reality (Wirklichkeit ). In Existenz, the Sein of the Dasein has been brought back to its foundation (Grund ), and Hegel can say that essence has "passed" into Existenz. In more formal terms, Existenz is defined as "the immediate unity of reflection-on-itself and of reflection on something else."
Contemporary philosophy. In post-Hegelian philosophy, and in particular with S. A. kierkegaard and K. marx, existence has asserted its primacy through definitions of the truth of being, although in different ways. In Kierkegaard and in Christian existentialism, existence lies in the act of freedom to choose the Absolute and to base oneself on it; in Marxism and in atheistic existentialism, on the other hand, existence is the choice of the finite. In Marxism this choice finds functional expression in the principles of collectivity and of class, while in leftist existentialism it finds expression as a function of the isolated individual.
In this way, existentialism and Marxism represent the distillation of modern philosophy. Putting the source of thought in doubt, they make the will and activity of the subject the foundation for the truth of both knowing and being, and this, as Hegel himself affirmed, following F.H. jacobi, through a "leap" (Sprung ) that is the dialectic itself. With such a subjective basis for the truth of being, will becomes the essence of the subject himself: modern metaphysics, therefore, as a metaphysics of subjectivity, considers the essence of being to lie in the sense of willing. Thus existence passes from simple "fact," "position," "state," or "mode" of the real to some principle like the fundamental act of subjectivity.
THOMISTIC NOTION OF ESSE
Greek thought, unable to transcend essence in act or to conceive creation as a total origin of being, limited itself to conceiving existence as a fact. Christian philosophy likewise stopped at the fact of creation and regarded existence as a "given" based on the dependence of creatures on divine causality. The scholastic expression of this concept was formulated by thinkers who maintained the real identity of essence and existence, conceding essence and existence the same meaning (and distinction) as the possible and the real. Modern thinkers, making a "decision" (will) in favor of radical doubt as the source of thought, progressively freed themselves from essence as "content" and foundation, and elevated existence to real and theoretical priority by seeing it as act and related to the structure of being. Thus did the absence of a theoretical basis for existence as act in antithomistic scholasticism influence the rise and development of modern philosophy.
Meaning of esse. St. thomas aquinas was unique in conceiving being as id quod est, that is, the real subsistent that is a synthesis of essentia and esse; the term existentia indicates, for him, the simple "given" or fact and has no special theoretical relevance. Aquinas took his point of departure, however, from Avicenna (In 1 sent. 22.214.171.124). The synthesis or compounding of essentia and esse constitutes ens; essence is the content and esse the activating action, and ens is related to and includes both (In 4 Meta. 2.558). The concept of ens commune, the most common predication for all things, but requiring further determination by generic, specific, and individual notes, differs markedly from the divine esse, which is pure act (De pot. 7.2 ad 6). The passage from esse commune to intensive esse is effected through the notion of participation. Ens is both concrete and universal in the sense of being the primary participant and the primary participation (In Boeth. de hebdom. 2).
In the synthesis that is ens, esse is the more formal principle, or the act par excellence, and this on two distinct levels. In the predicamental sense esse is the activation of essence, which itself is related to esse as potency (De pot. 7.2 ad 9). In the transcendental sense, to the extent that any other act or perfection pre-supposes and is founded on esse, the latter is the actualization of every act and the perfection of all perfections (Summa Theologiae 1a, 4.1 ad 3; 1a2ae, 2.5 ad 2). Esse is, therefore, the primary act, the simplest, most formal, most intimate, and most immediate (De anim. 1 ad 17, 9; De ver. 23.4 ad 7; Summa Theologiae 1a, 8.1; C. gent. 1.23). Consequently, as primary and absolute perfection, in itself including and transcending all perfections, esse is the most appropriate of all the names that can be attributed to God, or better—in light of the teaching on analogy— the least inappropriate (In 1 sent. 8.1.3; De pot. 2.1; Summa Theologiae 1a, 13.2). Thus understood, esse is the proper effect of God and indicates the radical production of creation that affects not only becoming but primary matter itself and pure spiritual substances (Comp. theol. 1.68; C. gent. 3.66). This can be called the "intensive notion" of esse, as distinguished from the notion of existentia of the formal-predicative kind of Aristotle and the formal-causal (extrinsic) kind of the Augustinian-Avicennian tradition.
Esse and God. Thus, while God is Esse as the simplest Pure Act that transcends every finite intellect, a creature is most properly called ens in the sense of id quod habet esse (In lib. de caus. 6). The very nature of the creature, by contrast with God who is the esse per essentiam, is to be an ens per participationem. This implies both the total dependence of creature on Creator (Comp. theol. 1.68) and the composition of essence and esse as two constitutive and really distinct principles, related as potency and act (De spir. creat. 1). Both derive from precisely the same metaphysical necessity, and the one presents itself as completing the other. In this unique concept of esse the following notions are unified: 1. The Biblical concept of God as "He Who Is." In reserving the name of esse for God, St. Thomas follows a constant Hebrew and Christian tradition. The former, beginning with philo (De vita Moysis 1.14), found technical expression in M. maimonides (Dux perplex. 1.57), while the latter was affirmed among the Latins by St. Augustine and among the Greeks by Pseudo-Dionysius (De div. nom. 1,5) and St. Gregory of Nyssa (C. Eunomium 8). 2. The Aristotelian concept of act as perfection and hence affirmation that is prior to and more perfect than potency. Thus, while there can be no potency without an accompanying act, act can well exist without potency (Meta. 1049b 10, 1051a 4). This metaphysical principle has its full intelligibility and truth only in the Thomistic concept of the ipsum esse, according to which God is called Esse Subsistens. The so-called formae subsistentes, the intelligences of Aristotelianism and of Neoplatonic emanationism are subsistent only in the formal sense, that is, as lacking matter, and not in a real way. In Thomism, esse is conceptually clarified through the Aristotelian notion of act, just as the speculative exigencies of the Aristotelian notion of act are fully realized only in the Thomistic concept of esse. 3. The Platonic concept of participation. The Aristotelian notions of potency and act, like those of matter and form, of substance and accident, and of particular and universal, find their basic expression in the difference between the participated and the participating. In esse these obtain a theoretical consistency that can be applied to entities whose existence is not subject to change and coming-to-be.
Originality of the Thomistic concept. M. Heidegger makes esse the goal and highest end of philosophy, but affirms that the problem is to "think of being without thought" [Der Satz vom Grund (Pfullingen 1957) 148–156]; St. Thomas, on the other hand, shifting the emphasis from essentia to esse in his notion of ens, furnishes a foundation sought in modern thought by radical doubt and in idealism by the transcendental.
St. Thomas does not consider ens, like other notions that are always determined in themselves, as defined species in a genus, for ens transcends genera and species: the principle is already in Aristotle (Meta. 998b 22–26), but Aquinas understands it more profoundly. Again, St. Thomas never derives the concept of ens from a reflective process of abstraction, but gives it an absolute priority in the intentional order as the principle through which all ther notions and insights are obtained (De ver. 1.1). Apprehension of ens is the first act of the agent intellect, which becomes the principle of development in the intellectual life (In 4 Meta. 6.605). This is followed by that of non-ens (De pot. 9.7 ad 15) and by the formulation of the principle of contradiction, which is the first principle of the intellect (Summa Theologiae 1a2ae, 94.2). Thus the notion of ens and the principle of contradiction flowing from it appear from the beginning in a transcendental sense and require practically a priori for understanding and furnishing an awareness of reality in terms of object and subject.
The absolute and necessary beginning of thought also finds its intentional expression in ens. This concept affirms the unity of perception of the knowing subject in the Thomistic sense of id quod est and id quod habet esse, and presents itself as the union of empirical experience, revealing being in actuality, and the act of the mind furnishing in a more or less confused way the content of reality as present. This initial evidence of a simultaneous sharing of ens between extramental reality and its apprehension by mind as present in act provides a basic reference for the structure of perception in general and for the later determination of the truth of being. The Thomistic notion of ens, therefore, expresses not only its original synthesis of essence and esse, but attests and guarantees the constitutive sharing of being in man and of man in being, explaining why man seeks himself in being and why being clarifies itself in man. Unlike the transcendental Ich denke, which reduces being to the objectivity of the object (see Heidegger, Der Satz vom Grund, 154), ens links man to reality while setting him apart from himself and from the world, so that he may transcend both the self and the world in the search for Ipsum esse as the transcendental absolute, principle and first cause of all reality and truth.
Knowledge of esse. Some modern authors hold that the Thomistic concept of esse, as an act of being in the strict sense, is seized by the mind in the act of judgment or in the synthesis of subject and predicate (F. Sladeckzek, K. Rahner, M. D. Roland-Gosselin, J. B. Lotz). They do this because they do not distinguish between existentia as an empirical datum (essentia in actu ) and esse as a most intimate and profound constitutive principle: The first is accessible to experience and expresses itself in the judgment, whereas the second reveals itself only to the most advanced metaphysical reflection. Existentia, therefore, is affirmed either through a judgment of perception that attains the present singulars or through demonstration by means of a principle of causality or of similarity (per signum ). Essence is known by abstracting the universal from particulars, based on an induction that is a function of the cogitative power influenced by the intellect and above all by the principle of contradiction; thus it expresses itself through definition and through judgments in the formal order of "nature considered in itself." The activity that unveils esse in Thomistic metaphysics has a unique character and could be called a resolutio that is proper to metaphysics. When St. Thomas attributes to simple apprehension the knowledge of material essences through abstraction and assigns the ipsum esse rei to the second act of the mind (In Boeth. de Trin. 5.3), he is speaking of an esse that pertains to the ontological, logical, and phenomenological orders, and not strictly of the esse that in God is His essence and in creatures is a substantial act distinct from essence and the effect of God Himself.
In Thomistic metaphysics, proceeding as it does from act to act, resolving the less perfect to the more perfect, the Esse Ipsum constitutes the final reference for every actuality. Its apprehension is neither intuitive nor abstract but rather a type of "dialectical emergence." Just as the apprehension of ens underlies the perception of reality, the apprehension of first principles, and the abstraction of essences, so the apprehension of esse as metaphysical act presupposes existential perception as much as intuition and abstraction, and is located at the apex of their convergence. It is obtained, for St. Thomas, by recourse to argumentation; this, however, is purely revelatory, bringing to light the originality of esse or demonstrating the real distinction between esse and essence in creatures and their identity in God. It is a "dialectical" kind of knowledge to the extent that esse as such is act and not content; thus the apprehension of esse occurs "by emergence," whereby the concept of act is approached as a first principle and foundation, and so reveals the ultimate stage of agreement between intellect and reality.
See Also: existential metaphysics; essence and existence; matter and form; potency and act.
Bibliography: c. a. hart, Thomistic Metaphysics (Engle-wood Cliffs, N.J. 1959). t. c. o'brien, Metaphysics and the Existence of God (Washington 1960). g. p. klubertanz, Introduction to the Philosophy of Being (New York 1955). l. de raeymaeker, The Philosophy of Being, tr. e. h. ziegelmeyer (St. Louis 1954). j. f. anderson, The Bond of Being (St. Louis, 1949). É. h. gilson, L'Être et l'essence (2d ed. Paris 1962); Being and Some Philosophers (2d ed. Toronto 1952). j. maritain, Existence and the Existent, tr. l. galantiÈre and g. b. phelan (New York 1948). c. fabro, "La problematica dell 'esse' Tomistico," Aquinas 2 (1959) 194–225; La nozione metafisica di partecipazióne secondo S. Tommaso d'Aquino (2d ed. Turin 1950); Participation et causalité selon S. Thomas d'Aquin (Louvain 1961); Partecipaziéne e causalité secondo S. Tommaso d'Aquino (Turin 1960); "Dell'ente di Aristotele all' 'esse' di S. Tommaso," Aquinas 1 (1958) 5–39; "Dell'ente, dell'essere e del nulla," La Philosophie et ses problèmes … études … offert à R. Jolivet (Paris 1960); "Per la determinazione ell' "essere," Tijdschrift voor Philosophie 23.1 (1961) 97–129; "The Problem of Being and the Destiny of Man," International Philosophical Quarterly 1 (1961) 407–436. a. thalheimer, Meaning of the Terms: "Existence" and "Reality" (Princeton 1920); Existential Metaphysics (New York 1960). j. de finance, Être et agir dans la philosophie de Saint Thomas (Paris 1945). j. b. lotz, Das Urteil und das Sein (Pullach-Munich 1957). j. hegyi, Die Bedeutung des Seins (Pullach-Munich 1959). a. marc, L'Idée de l'être chez Saint Thomas et dans la scholastique postérieure (Paris 1933).