Aquinas supplies ready evidence of Avicenna’s influence as well as the nature of the scholastic reception suggested above. In his commentary on Aristotle’s Metaphysics, he offers what will become the general characterization of Avicenna’s position in the Middle Ages. There, he writes that Avicenna is correct to assert that existence is other than its essence, but, if existence as ‘‘occurring to’’ (accidit ei) an essence is to be understood as a kind of accident, then he misspoke (bk. 4, lect. 2, n. 558). (For an argument that this is not what Avicenna is doing, see Rahman 1981.) Aquinas does not want us to see a thing’s existence as something different from the concrete existing individual itself. He writes that ‘‘it designates the same thing as the term which is applied to it by reason of its essence’’ (n. 558). While Aquinas’ position on essence and existence is most famous for its insistence on a real distinction between essence and existence, he does not allow himself to suggest that essence might have an existence of its own or some reality apart from its existence: thus, his rejection of Avicenna’s language of existence as ‘‘occurring’’ to an essence.
Aquinas’ most definitive treatment on the subject is, of course, found in his treatise De ente et essentia. This is one of Aquinas’ earliest works and marks the beginning of the most formative period of the dispute over essence and existence. In this work, he indicates one of the major theological issues at stake in this question for thirteenth-century theologians. He also provides one of the key arguments that will be considered again and again either as support for the real distinction or as an argument that must be refuted.
The key theological issue at stake for Aquinas is the simplicity of God. Aquinas’ metaphysical presuppositions force him to deny any material composition in angels. But this leaves him with a real difficulty of explaining just why angels do not possess the same absolute simplicity as God. He finds his answer to this conundrum in the real distinction between essence and existence. While angels do not have a material composition, they remain like other material creatures on account of the fact that their existence is not their own, but is received from another (DEE, c. 4, para. 6).
The most compelling argument that Aquinas gives for this distinction and the consequent complexity in creatures is found in the fourth chapter of his treatise. He argues that whatever cannot be conceived of apart from something is in no way distinct from it. But, he reasons, the essence of man and of a phoenix, for that matter, can be conceived without being conceived as existing. Thus, their essence and existence must be distinct (DEE, c. 4, para. 6). Those who want to deny the real distinction will repeatedly face this objection and more often than not will deny the minor premise, viz., that an essence can truly be conceived without also conceiving its existence.
Aquinas’ treatise marks one of the first formalized scholastic defenses of the real distinction. However, his is not the only influential voice. In fact, what later came to be identified as the Thomistic position may owe less to Aquinas himself than to one of his students, Giles of Rome. Giles treats the distinction between essence and existence in several places, but his two most explicit works on the topic are his Theoremata de esse et essentia and his later Quaestiones disputatae de esse et essentia. With these two works, undoubtedly influenced by his well-documented disagreements with his Parisian colleagues, Henry of Ghent and Godfrey of Fontaines, Giles established himself as one of the central disputants in perhaps the most contentious debates at Paris during the 1270s and 1280s.
Though divine simplicity seems to be the dominant concern of Aquinas, in these works and others, Giles repeatedly indicates that he thinks the real issue at stake here is the possibility of creation and the truly contingent nature of reality. Without a real composition, Giles argues that all creation is impossible and all reality is in fact necessary (e. g., TCC, prop. 29). This is something that comes out clearly in the fifth theorem of his Theoremata as he provides an analogy as to how we are to understand this composition. He writes: ‘‘to understand the creation of beings, which requires a composition of essence and existence, we may think of that kind of generation which Plato speaks of’’ (TEE, th. 5, Murray 1953:37). Giles is referring to the way a Platonic Form, even as it enters into a kind of composition with the particular thing, remains its own distinct and separate entity. He compares this to the way the ‘‘self-existing’’ existence remains separate from the existence of a thing, ‘‘in so far as from this separate existence the existence flows into the essence of a creature in which the essence participates” (TEE, th. 5, Murray 1953:37).
Two elements of this description need to be emphasized since they are repeatedly affirmed by Giles. The first is that existence must be seen as its own reality apart from its attachment to any essence. Thus, the composition of essence and existence must be seen as a composition of two things (duae res) (e. g., TEE, th. 19; QDEE q. 9). The second, which follows from this, is that Giles, unlike Aquinas, introduces the separability criterion of the real distinction; namely, he insists that essence and existence are, in principle, separable things. Both of these elements will become essential components of the standard formulation of the real distinction. Likewise, it will increasingly become the standard description of the Tho-mistic position, much to the dismay of those Thomists who believe Giles has severely distorted the true position of Aquinas.
Giles is not immune from the critiques of his own contemporaries either. While among them is, as noted above, Godfrey of Fontaines, his most severe critic is Henry of Ghent. Henry looks at Giles’ description of essence and existence as two realities (duae res) and insists that if essence is going to be considered an independent thing apart from its affirmative or actual existence, then essence and existence cannot really be distinct (Quodlibet 1, q. 9). In order to explain why this is so, Henry introduces what he calls an ‘‘intentional distinction’’ between essence and existence. With echoes of Avicenna in the background, Henry argues that if essence is separable and prior to its actual existence in the world, as Giles suggests, then it must retain a kind of existence and therefore cannot really be separated from existence. To clarify his position Henry identifies two kinds of existence: the being of the essence (esse essentiae) and the being of existence (esse existentiae). Henry insists that an essence prior to its creation has a kind of existence that it receives from its formal cause (i. e., the ideas of the divine mind or the divine exemplar). To say something has esse existentiae, therefore, is not to attribute existence to something that previously existed without existence (as if this made sense), nor is it to attribute existence to a thing twice. Rather, it is to indicate a new relation of efficient causality in addition to the relation of formal causality between God and the creature. Thus, Henry concludes that there is not a real distinction between essence and existence, but an intentional one (Quodlibet 10, q. 7). While notoriously ambiguous, the notion of an intentional distinction is generally taken to mean that there is a recognizable difference between a thing’s existence and a thing’s essence that is not merely a product of the mind. Nevertheless, contra Giles, there is no sense that essence and existence can ever be truly separate or that one can be entirely without the other.
Besides the disagreement over terms and formulations, Henry’s different position can also be attributed to a difference in concern from either that of Aquinas or Giles. While Aquinas is concerned with divine simplicity and Giles is preoccupied with preserving the possibility of creation, Henry is most explicitly concerned with preserving a kind of scientific knowledge of possibilities. For him, having knowledge about the merely actual is deemed insufficient as long as the actual could, in principle, be different. To have knowledge, then, derived from what is merely possible is thought to provide a much higher level of certainty. One of the most conspicuous places where this concern is raised is in Henry’s interest in the proofs for God’s existence. Knowledge of God’s existence derived from the actual existence of a creature was thought by Henry to be inferior and less certain than knowledge of God’s existence derived from the mere possibility of crea-turely existence (see SQO a. 25). However, in order for such knowledge to be possible, he needs to find an object of such a science. Clearly, the ability to posit a kind of existence for not yet actualized, but possible, essences is a key component of preserving this kind of knowledge.
While the voices of Aquinas, Giles, and Henry are certainly the most influential for any further discussions of the distinction within the scholastic tradition, some of the earliest historical perspectives on this distinction divide up the history of the dispute slightly differently. No one has done more to shape the way we think about the history of the dispute than Francis Suarez. In his 31st question of his Disputationes metaphysicae he recognizes three distinct schools of thought.
The first school is what Suarez labels the thomisticae. He asserts that this school holds that the distinction between essence and existence was a distinction between duae res, two distinct or independent realities that could in principle be separated (DM 31, I, 3-10). Thus, we can see how dramatically the influence of Giles would come to distort the original position of Aquinas for centuries.
The second school is identified as the scotisticae. Suarez describes the distinction defended by Scotus and those of his school as a modal distinction between the essence as a genuine reality and its existence as particular mode of being. While this is the picture that posterity attributes to Scotus, we receive little clarity on the matter by looking to Scotus himself. Scotus devotes little to no explicit positive attention to how he views the relationship between essence and existence (O’Brien 1964:61). What little there is to be found comes indirectly from a discussion on the nature of Christ and his human existence (Ord. III, d. 6, q. 1). From this discussion, Suarez concludes that this modal distinction is a weaker type of real distinction, where the essence remains an independent reality, but that the same cannot be said of existence. As a mode, existence acquires an ontological status similar to that of whiteness, which cannot exist without a subject, even though the subject can exist without whiteness (DM 31, I, 11). Contemporary scholars remain divided over whether Scotus ever actually recognized a modal distinction and where it fell among the distinctions of real, formal, and rational. Suarez further shows his lack of historical precision on the matter by attributing this position to Henry of Ghent as well. While this is not a particularly accurate description of Henry’s position, Suarez certainly characterizes him this way because of the resemblance of the intentional distinction to Scotus’ modal distinction.
Finally, Suarez points to a third historical position, which asserts that the essence and existence of a creature are distinguished by reason alone. Under this heading, Suarez includes an eclectic mix of people that cannot be said to form one particular school. Here, he includes Godfrey of Fontaines, Durand of St. Pourcain, Peter Auriol, and Gregory of Rimini among many others (DM31,1,12). Having mentioned the nominalist Gregory of Rimini, it is notable that Suarez fails to mention William of Ockham, who should be included in such a list. And while no one position can capture such an eclectic mix of people, Ockham’s rejection of any thing other than a rational distinction between essence and existence is notable for its simplicity and reliance on the formulation of the real distinction provided by Giles. In Quodlibet 2, q. 7, Ockham considers the claim that essence and existence are two distinct things (duae res) and therefore separable. He concludes that if essence and existence are really two things, they must be either substances or accidents. But, being neither, they therefore cannot be two things nor can they be separated. Thus, no real distinction exists.
World History
