In the summer of 1932, when Jacques Maritain finished The Degrees of Knowledge he was at the beginning of the road that was to lead him to an existential Thomism, that is a Thomism increasingly centered on the primacy of the act of existing. Therefore, when he took up his pen to write an Appendix to The Degrees called “On the Notion of Subsistence,” he wrote in a long, involuted but not atypical sentence: 

“If we take exact account of the special conditions which the doctrine of potency and act assumes in the case of essence and existence, we can see that the notion of subsistence as a substantial mode is not Cajetan’s invention but rests upon the fundamental principles of Thomistic thought, and upon what must be considered – if not as St. Thomas’ own discovery (for the neo-Platonists, and Avicenna after them, had already suggested or taught the real distinction between essence and existence in creatures), at least as the truth singled out by him, with incomparable lucidity, to be the foundation of the whole metaphysical edifice – I mean of the extension of the Aristotelian doctrine of potency and act to the relation of essence to existence.”¹

Perhaps the “if not as St. Thomas’ own discovery” is his way of telling us that he has begun to see more clearly than ever before the depths of the metaphysical revolution that Thomas had wrought. But if this is so the challenge that faced him was a difficult one. Could he take subsistence which was, as he had announced in the first line of this appendix,  “one of the most difficult and controversial in Thomistic philosophy,” and shed new light on it by seeing it in terms of a deeper understanding of the relationship between essence and existence? 

The relationship between potency and act, he tells us, finds an “altogether unusual” application in the relationship between essence and existence: “An essence which is completely achieved in its line of nature, is potency with respect to the act of existing…”² The “completely achieved” is significant, for it shows how essence and existence still maintain a significant degree of independence in his mind. Maritain will go so far as to say, “Essence and existence belong to two different orders…”³ and to reason that in contrast to all other activations of potency, existence is not the activation of “potency’s own reserves of determinability.”⁴ Even though existence causes essence formally to be, “there is a sort of transcendence of the act of existing,”⁵ in regard to essence, for it is not “the achievement of essence in the order of essence…”⁶  Therefore – and this is the pivotal point – existence, “does not form part of the order of essence.” Essence “with respect to its quidditive constituents, has not in itself anything by which to make ITS OWN” the act of existence.⁷

Essence still needs some way to make existence its own. It needs to be terminated in regard to existence and limit existence to itself, and what does this is the substantial mode called subsistence. Subsistence is neither a quidditative constituent of essence, nor is it yet existence. Put in less philosophical language we can imagine it as a certain final finishing, or perfecting, of the essence that allows it to bridge the gap between itself and existence. Or put in Maritain’s more elegant metaphysical language: “Thus, subsistence appears as a sort of individuation of the essence with respect to the order of existence, leaving the line of nature to face up to something altogether different, to make the leap into existence; a sort of individuation by whose means the essence, individuated in its own life, appropriates to itself alone the existence it receives.”⁸ Essence, in short, needs a “last metaphysical complement,” an ultimate disposition to receive existence.

Despite the brilliance of Maritain’s thought, there is something in all this that can make us uneasy. How primary can existence be in regard to essence if essence and existence form two orders and essence needs the help of subsistence to leap into existence? What we are seeing is, perhaps, the very beginning of Maritain’s deepening metaphysical understanding that was soon to blossom in his Sept leçons sur l'etre et les premiers principes de la raison spéculative which followed hard on the heels of The Degrees and was one of the sources that Etienne Gilson was to later draw upon when he, himself, described an existential Thomism. Here though, Maritain, faced with the intractable problem of subsistence, makes only limited headway in aligning subsistence with the primacy of existence.

This appendix continued to appear in The Degrees, long after Maritain’s  understanding of the metaphysics underlying it had been transformed, with the justification that it represented a “certain typical approach to the problem.”⁹ Then in 1954 he finally decided to revise it by adding “On the Notion of Subsistence, Further Elucidations.” These revisions allow us to gauge something of the trajectory of the development of Maritain’s metaphysical thought in the intervening years and these two versions of the appendix can serve as mileposts that point to a deeper understanding of subsistence as seen against the background of the  relationship between essence and existence.

If we are going to have a deeper understanding of subsistence, Maritain tells us in this second version, we have to direct our attention, not to essences, but to subjects, or existents from which the universal essences found in our minds are derived. And further “essence is potency in relationship to existence.”¹⁰ These considerations lead him to a new understanding of subsistence. There is “an intuition of existence,”¹¹ in which existence, or esse, is perceived as an “exercised act,” “an activity in which the existent, itself, is engaged, an energy that it exerts.”¹²  Essence does not need subsistence in order to receive existence, and limit and circumscribe it to itself, but to exercise existence, the essence has to be completed by subsistence. “(E)ssence, or nature can receive existence only by exercising it.”¹³ And to do this it needs to be drawn out of the essential order and “placed in an existential state which makes of it a quod capable of exercising existence.”¹⁴ 

Maritain’s thought is clear and formal on this point. Subsistence allows essence “to transfer into the existential order.”¹⁵  Subsistence is a “new metaphysical dimension, a positive actuation or perfection.”¹⁶  It is “a kind of ultimate disposition for the exercise of esse.”¹⁷  And all the while he is saying these things, he is also insisting on the supremacy of esse in regard to essence: “Esse is not received by the essence as in a pre-existing subject which would thus already be an existential act. The essence which receives existence holds from it – in what concerns the existential order – absolutely all its actuality, in short is nothing without it.”¹⁸ Or, along the same lines, “…esse to actuate the supposit is (in virtue of the divine action compenetrating it) to be the fundamental and absolutely first activity of the supposit in its substantial intimacy and depths – activity eminently its own when the supposit is a person – by which it is other than nothing.”¹⁹

As Maritain saw in these further elucidations on subsistence, there was no need for an essence to be terminated by subsistence in order to receive existence. Therefore, he insists that subsistence is necessary to allow essence to exercise existence. But is it possible to go farther down this road towards an existential Thomism? Just what is subsistence? If subsistence belongs to the order of essence, it is not in any way actual, and cannot bridge the gap between essence and existence. If subsistence belongs to the existential order, then it is already an effect of the act of existence, and not a preparation for it. Does essence really need to be placed in a state of exercising existence, to be “transferred” into the existential order? If subsistence is “a new metaphysical dimension, a positive actuation or perfection,” this perfection must be the result of the act of existing, itself. But if it is the result of the act of existing, itself, then how can it be a preparation for it? Is there really a “transcendence” of existence in regard to essence? Subsistence allows essence, Maritain tells us, to leave the essential order and enter the existential one, but can we not say that this is precisely what existence, itself, does? Why not say that subsistence is the essence in the very act of receiving existence, at the very moment of being actualized so that it begins to exist precisely when it begins to exercise existence? Or better why not say that as our sense of the primacy of the act of existing grows subsistence vanishes?

What would happen if we let subsistence vanish? Would the whole Thomist metaphysical edifice tremble and collapse? I don’t think so. The act of existing does not fill up an essence as if it were some pre-existing receptacle, rather essences of their very nature are certain capacities for existence, and therefore limit the act of existence so that this or that existent can come into being. The activation of essence by existence turns essence from a possibility to an actually existing being. We may, if we wish, call subsistence essence in the act of being existentialized, brought into existence, receiving existence, and exerting the first and fundamental energy of existence which makes it to be something that exists. But just as essence receives existence of its very nature, it exercises existence without further ado. It does not need subsistence in order to bring it into relationship to the order of existence.

Thus, the more we follow the road that Maritain pursued in these two versions of the Appendix on subsistence, the more subsistence vanishes, and the more its place it taken by the primacy of the act of existence to which essence is totally oriented. We are moving in a direction that says that essence which is this or that in the quidditative order has not the slightest shred of existential activity. It does not possess any actuality in the existential order. The whole order of essence is subordinate to the existential order to such a degree that we need not talk about two orders, but only one, in which essence is potency to existence. Essence is a certain capacity in regard to existence. The very essence of essence is its existability, its potency for existence. Essences are real, but only as potencies or capacities or existabilities for existence.

From a philosophical perspective, then, it is possible to imagine moving in the direction of an ever more existential Thomism and seeing subsistence vanish. But the notion of subsistence that Maritain is dealing with had long, complex historical antecedents stretching back to the struggles in the early church to elaborate a theology of the Incarnation. With St. Thomas and his commentators this theological history interacted with Thomas’ metaphysical revolution, and we are faced with a series of questions that we must note, but whose answers we can leave to the historians of Thomism. To what degree, for example, did Thomas’ commentators like Cajetan grasp the full import of Thomas’ new insight about the relationship between essence and existence? If they still set forth an essentialism, to what degree did that influence their views on subsistence? Isn’t it possible that they emphasized subsistence’s role as a way to join essence to existence precisely because they needed to overcome the essentialism that ironically they had introduced into the thought of St. Thomas in the first place? (And isn’t it possible that Thomas, himself, was inconsistent with the way he applied his insight into esse to the notion of subsistence?) And couldn’t the thesis of the Thomist school that the humanity of Jesus lacked a human existence, whose role was taken by the divine existence, be a logical outcome of this essentialism of the commentators?

If we could answer these latter questions in the affirmative, then we could understand how Maritain, working out of this tradition, would have had to struggle to bring his deepening insights into the primacy of existence to bear on the notion of subsistence so that in the first version of his Appendix on subsistence he still affirms that essence needs subsistence to receive existence, and that the human nature of Jesus lacked not only subsistence, but existence. It was H. Diepen’s criticism of this “ecstasy of existence” in 1950 in the Revue Thomiste that Maritain tells us helped encourage him to write his second version, and brought home to him how the theological context of subsistence had influenced him before, and how he now needed to try to set forth a properly philosophical view of subsistence.

Even if we don’t need to enter these historical thickets in order to answer these questions, there is one we cannot avoid. Does the vanishing of subsistence have untold theological consequences that would, therefore, indicate that we have been over-hasty in its elimination? The notion of subsistence, after all, was a way to assert that while Jesus had a true human nature, there was only one divine person, so the unity of his personality was preserved. But the traditional Thomist line of reasoning makes us think of subsistence as something distinct from essence, or nature, playing a role, as we saw, of allowing essence to exist, and so without subsistence it is easy enough to take the next step and see the human nature of Jesus without a human existence. By the time of the second Appendix Maritain had realized that this position was untenable, but in order to safeguard the unity of Jesus’ personality, he asserts that while his human nature receives existence, it does not exercise it, and so it is without a human subsistence.

More technically he outlines this position in a series of points in which he tries to capture the mind of St. Thomas on the matter. Just as there is only one subsistence in Christ, there is only one personal existence; there is, however, a created existence; but this existence is received but not exercised; the human existence is exercised by the divine person; but the human existence does not contribute anything to the divine existence; it belongs to it; the humanity of Jesus is joined hypostatically and personally to the person of Jesus; and finally, the human existence of Christ is “a simple, temporal and created echo” of his uncreated personal existence.

While the thrust of these points is clear, we can still ask from a philosophical point of view whether essence can really receive existence without exercising it. Isn’t the heart of Maritain’s intuition of existence the insight that existence, precisely as existence, is exercised, is an energy that the existent subject exerts? How could it not exert this energy and still exist? Therefore, it appears that the reception of existence and its exercise are two sides of the same event, an event that does not seem to demand subsistence. But does that mean that the elimination of subsistence dislocates important elements in the theology of the Incarnation and introduces a duality in the personality of Jesus? I don’t think so. What we need is another vantage point from which to look at the humanity of Jesus, and Maritain in both these Appendixes has provided us with some starting points.

In the first version, for example, Maritain speaks of the human nature of Christ “which subsists and exists by the divine subsistence and the divine existence” without the divine entering into composition with the human. And this is made possible by “the privilege of the infinite subsistence of a person whose nature is identical with his existence and is eminently all things.”²⁰  There is a total transparency of the human nature to the divine nature, for every creature flows from its source which is the divine existence, itself. The human existence of Christ is in no way in opposition to his divine existence as if there could be something in it that would be an obstacle to his assumption in the Incarnation.

In the second version of the Appendix, he cites St. Thomas from his De Unione Verbi Incarnati – which previously Maritain had thought was inauthentic – where Thomas talks of the existence of the human nature of Christ being not the principle existence of his supposit, but a secondary existence.²¹ And Maritain likens this secondary existence, as we saw before, to “a simple, temporal and created echo… of his uncreated personal existence.”²² The human existence of Jesus’ human nature cannot, as we have just seen, be in opposition to the divine existence, but what does Maritain mean by talking about a “simple, temporal and created echo”?

In a fascinating footnote in the second version, we can see the kind of struggle that Maritain is having. He asks about the meaning of St. Thomas’ teaching that Christ’s human nature has no subsistence of its own. “Does St. Thomas’ teaching on this point indicate that the uncreated subsistence acts as subsistence for the human nature by divinely conferring on it the completion which created subsistence, of which this nature is deprived, would confer on it? Or does it indicate that the uncreated subsistence renders useless the human nature’s being perfected or completed by such a completion? For our part, we believe that it is the second interpretation that is better founded. In other words, a human nature, on which this mode or state in which subsistence consists is not at all conferred, is assumed, possessed and used by the eternally subsisting Person of the Word.”²³  The human nature of Jesus, Maritain is telling us, is not so much deprived of subsistence as it is in no need of it because it is assumed by the Person of the Word. He goes on to say that the divine subsistence by this assumption of the human nature “does not perfect it itself and render it itself subsistent, it dispenses it from subsisting, or from being itself achieved and completed by that mode or state in which subsistence consists.”²⁴  

Maritain’s footnote still contains unresolved tensions. How do we reconcile the absence of subsistence in the human nature, or it being rendered useless, with Maritain’s understanding that subsistence represents a certain perfection, the perfection of allowing the essence to exercise existence? How can we avoid ending up feeling that something important is lacking to the human nature of Jesus? Maritain is caught between his need to say that this human nature is without subsistence in order to preserve the unity of Jesus’ personality, and his desire not to deprive Jesus’ human nature of anything essential. And this is a delicate balancing act when he continues to insist on defining subsistence in terms of exercising existence.

If in the footnote we have just been examining Maritain is groping towards a deeper view of the human nature of Jesus, at the end of this second version of his Appendix on subsistence, he actually opens up a pathway that was to lead to one of his final books, On the Grace and Humanity of Jesus. The incarnate Word in his earthly life acts by way of his human nature. He uses it as an instrument of his human activity.

“And according as He was man that which pertained to His state as comprehensor was reserved, so to say, for heaven by reason of the exigencies of His state as viator. Even the share of His human soul in the Divine Life – the beatific vision which it enjoyed here below – remained a paradise above, sealed off from its faculties… For, indeed, the beatific vision, being of itself strictly ineffable, shone on the highest part of the soul without being expressed in any concept or communicable idea…

“We ask ourselves, or rather we ask theologians, if the conclusion to be drawn from this is not that the supreme evidence that Christ, in His human soul, had of His own divinity by the beatific vision did not pass into the experience of Himself proper to the homo viator in the form only of an absolute certitude or knowledge which was sur-conscious or super-conscious (I mean retained at the supreme spiritual point of consciousness), and neither signifiable in concepts nor communicable?”²⁵  This is the seed of a deep intuition that was to blossom later in On the Grace and Humanity of Jesus where Maritain sets forth a psychology of the Incarnate Word. But this divinization of the humanity of Jesus points to a way in which to reevaluate the notion of subsistence in regards to Jesus’ human nature. Instead of saying this human nature lacks subsistence, why could we not say that precisely by being the human nature of the Word it is transformed and elevated. It received what Emile Mersch, in his The Theology of the Mystical Body, called an entity of union, a new way of existing in virtue of being the humanity of the Word. There is nothing in the existence of the human nature of Jesus that resists being united to the divine existence, but instead of saying that this means that the human nature of Jesus lacks existence (first version), or subsistence, which is the exercise of existence (second version), we could say that this human nature, far from being deprived of anything, is intensified by its union with the Word and becomes a more deeply human human nature. The human existence of this nature is taken up in a higher way of existing that does not negate it, but enriches it so that it is not just a human personality in the modern sense of the term, but a human personality that has been elevated and transformed into a divinely human personality. The “lack” of subsistence in Jesus is, in fact, a higher and deeper way of being human.

In final analysis, therefore, there appear to be no philosophical reasons why we cannot let subsistence vanish, and no theological reasons, either. But to do this we have to pursue the path of a more existential Thomism and a deeper view of what happens to the humanity of Jesus in its union with the Word.

Notes

1. Jacques Maritain, Distinguish To Unite or The Degrees of Knowledge, Newly translated from the fourth French edition under the direction of Gerald Phelan, New York, Charles Scribner's Sons, 1959, p. 430.

2. Ibid.

3. Ibid.

4. Ibid.

5. Ibid.

6. Ibid., p. 431.

7. Ibid.

8. Ibid., p. 433.

9. Ibid., p. 434.

10. Ibid., p. 436.

11. Ibid.

12. Ibid.

13. Ibid., p. 437.

14. Ibid.

15. Ibid., p. 438.

16. Ibid.

17. Ibid., p. 439.

18. Ibid., p. 437.

19. Ibid., p. 439.

20. Ibid., p. 432.

21. Ibid., p. 435.

22. Ibid., p. 442.

23. Ibid.

24. Ibid.