Metaphysics and Ontology II

B.  The Question of the Distinction between the Essence and the Existence of a Thing

It is important to realize that medieval philosophers assumed a very large ontological domain.  They needed not only to account for the metaphysical constitution of the material objects encountered in the world, but also incorporeal beings like God, angels and human souls. While God's metaphysical simplicity and His necessary, uncaused character presented a unique challenge to general metaphysical principles, created entities such as angels seemed to cry out for a metaphysical framework of the created order wide enough to include their constitution. The medieval question of the relationship between essentia (essence) and esse (existence) in created beings arose because of the need to cast a metaphysical account broad enough to include both corporeal and incorporeal created beings.

Boethius first suggested that entities had two aspects: essence and existence.  In Axiom II of his De Hebdomadibus, he writes, Diversum est esse et id quod est . . .   In Axiom VIII he opines, Omni composito ilid est esse, aliud ipsum est (Wippel, 392, fn. 38).  These comments seemingly conform with Avicenna's view that existence and existence are robustly distinct. Averroes and followers demurred, arguing that if an object has real being only by virtue of that which is superadded to essence, then why not claim there is something else superadded to existence making it even more real (393)?  Boethius' comments and the differing interpretative traditions of Avicenna and Averroes set the stage for this metaphysical controversy.

Aquinas advocated the real metaphysical constitution of essence and existence, suggesting in his youthful De ente et essentia that essence or quiddity is the potency of any created being which can be actualized into existence by God.  While the first is necessary for understanding of the thing, the second is not, coming, as it were, from outside the thing's quiddity and uniting with its essence in composing the real thing.  In the Summa contra Gentiles Thomas writes, . . . et sic in quodlibet creato aliud est nature rei quae participat esse, et aliud ipsum esse participatum (SCG I, q. 13).  The participating nature is in potential to the actuality of the participated nature. As Wippel points out, over and against Avicenna, for Aquinas, since "existence has no quidditative content in addition to that of the essence which it actualizes," . . . "neither essence nor existence can exist independently of each other"(395).  Thomas writes: Unde patet quod hoc quod dico esse est actualitas omnium actuum, et propter hoc est perfection omnium perfection (q. 7, a. 2, ad 9).  To say that existence (esse) "is the actuality of all acts and the perfection of all perfections" is to claim that ens (a being) participates in esse (to-beness).  Essentia both receives and limits esse and thereby produces ens. Real composition is necessary in a being in order to account for the quidditive limitation of that being.

While Aquinas held to the real distinction of esse and essentia, he did not employ the infelicitous language of Giles of Rome who asserted in his Theoremata de esse et essentia that esse et essentia sent duae res (th. 19, p. 127), and that since res ergo ipsa quod est esse est in genere substantiae, it is per consequens intelligitur quod esse sit alia res ab essentia (Giles, q. 9 & q. 11, in Wippel, p. 392).  Giles clearly is trying to account for all of created being in analogy with the form/matter distinction for material entities: Dicemus ergo sicut generatio facit scire materiam aliud esse a forma, sic creatio facit nos scire essentiam esse aliud ab esse (th. 5, q. 9).  Giles' use of res in characterizing both esse and essentia suggests a very robust, real esse/essentia distinction, and it was his formulation of real distinction that was severely criticized by Siger of Brabant, Godfrey of Fontaines and William of Ockham.

Siger admitted that ens was composite, but instead of construing this composition along the form/matter analogy, he suggested that the analogy between substance and accident is better.  Godfrey claimed the distinction was only secundum rationem (according to reason) and not due to the metaphysical composition of the thing.  Godfrey, in fact, argued for a real identity between esse and essentia, for whatever can be said truly of the first can be said truly of the second and vice versa (Wippel, p. 401).  Essentia has only potential being prior to God's bringing it to be.  Since the significatio of essentia and esse are the same, the two must be identical.  Ockham mounted ingenious philosophical arguments against the real distinction of esse and essentia, claiming that if former were really distinct from the latter, then it would have to be either a substance or accident.  But it is neither an accident because esse is not a quality or quantity, nor a substance because esse is neither a matter, form, their composite, or a separate entity (Wippel, p. 402).  His modal argument precedes thusly:  If a and b are distinct then it is possible for a to obtain without b, or for b to obtain without a.  But it is not possible for God to create essentia without esse or esse without essentia, therefore esse and essentia are not distinct.

Henry of Ghent, James of Viterbo and Duns Scotus sought to establish a position between a real ontological distinction between esse and essentia, and their ontological identity which possesses only a distinction according to reason (secundum rationem).  Henry of Ghent's views, though not widely affirmed in the subsequent tradition, are nevertheless quite interesting.  Anticipating Meinong, he affords a type of being to essences (esse essentiae) that is not existential.  Because God exists and has knowledge of all possible and existing entities, essential being has a type of existence prior to actual existential instantiation.  The divine will thus communicates actual existence (esse existentiae) to a subclass of esse essentiae entities.  Henry ingeniously opts for a new type of distinction, one of intention, in sorting esse and essentia.  While the existence of a thing does not add to its essentia, the external relation of actually being efficiently caused by God in creation marks a third path between a real distinction and real identity.  Esse essentiae is sorted from esse existentiae) by the fact that God has actually created the second.

James of Viterbo apparently tried to distinguish between essentia and esse semantically, according to primary and secondary significance.  While the modus significandi (mode of signification) of an abstract term signifies only the thing's essence, that of a concrete term, while signifying essentia primarily, signifies secondarily the thing having esse.  So existentia signifies essentia primarily and secondarily it signifies that which is conjoined with essentia in an existing subject (Wippel, p. 405).  Finally, and most famously, Duns Scotus searched for an intermediate position by admitting that while esse and essentia are not separable in contingent fact, they are not identical in all possible worlds.  Although oftentimes referred to as the "formal distinction," Scotus scholars have differed on what precisely is meant.  Scotus also opines that while abstract cognition has essentia as its proper object, intuitive cognition has existentia.  Whether either this epistemic point or the modal point legitimately establishes a formal metaphysical distinction between things never found apart is, of course, open to further debate.