0. Introduction. I am in the process of preparing myself, and hardly for the first time, for an effort at coming to a determination of whether the arguments for the existence of God set forth by Thomas Aquinas in the Summa Theologiae are valid and sound, valid but unsound, or simply invalid. As the first step in the process, I have begun a systematic study of the thought of Réginald Garrigou-Lagrange, O.P. I am currently reading and rereading the early chapters of his Reality. A Synthesis of Thomistic Thought.* I plan thereafter to move on to reading and rereading the early chapters of his The One God. A Commentary on the First Part of St. Thomas’ Theological Summa.** Then, finally, assuming that I then assume myself adequately prepared, I will take up the reading and rereading of his God. His Existence and His Nature. A Thomistic Solution of Certain Agnostic Antinomies; it is in God. His Existence and His Nature that I expect to find one of the most compelling expositions of the arguments.

There is much, of course, in the philosophical thought of Aquinas and, following him, Garrigou-Lagrange with which I find myself in agreement. I heartily concur, for example, with the substance, if not always the expression, of what they have to say about the first principles. I have no quarrel either with their treatments of the theory of act and potency, at least insofar as that theory is offered as the basis of the solution to the theory of change.

1. The First Question. But there are some theses in the philosophical thought of Aquinas and, following him, Garrigou-Lagrange, which, whether or not they have an immediate bearing on the argument for the existence of God, leave me wondering, well, whether they are true. A number of such theses appear in Garrigou-Lagrange’s discussion, in Reality (pp. 37-38), of the central Thomistic thesis that “act is limited by potency.” There Garrigou-Lagrange tells us:

Aristotle had already taught this doctrine. In the first two books of his Physica he shows with admirable clearness the truth, at least in the sense world, of this principle. Act, he says, is limited and multiplied by potency. act [sic] determines potency, actualizes potency, but is limited by that same potency. The figure of Apollo actualizes this portion of wax, but is also limited by it, enclosed in it, as content in vessel, and as such is thus no longer multipliable, though it can be multiplied in other portions of wax or marble.

There are in fact many theses being affirmed here, signaled by the occurrences of “and,” “but,” and the commas. I’ll take note of three. The first I’ll accept, without further ado:

Act determines, or actualizes, potency.

The second is the thesis that:

Act is limited by potency.

The third is the thesis that:

Act is multiplied by potency.

The third thesis I’ll set aside for now, as I intend to address it in a subsequent post, one devoted to the problem of universals.

It is the second of the three theses that I find myself failing to understand and to which I want to draw attention. I find myself asking:

How can it be that act is limited by potency?

That is, if act can be limited by potency, then does that not entail that act is capable of being limited or is, in other words, potentially limited? That is, does that not entail that act is determinable and that, accordingly, potency is determining or actualizing?

2. The Second Question. Garrigou-Lagrange continues his discussion, telling us that, according to Aquinas:

Form, act, perfection, precisely by being received into a really containing capacity, is thereby necessarily limited (made captive) by that container. Under this formula, the principle holds good even in the supersense order: Act, he says, being perfection, can be limited only by the potency, the capacity which receives that perfection.

He next presents two central theses of the “existentialism” of Aquinas:

Now, he [Aquinas] says, existence is actuality, even the ultimate actuality. And he develops this thought as follows:

He, Garrigou-Lagrange, then proceeds to quote the passage from Aquinas’s Summa Theologiae (Ia, Q. 4, art. 1, ad 3) in which the thought is developed:

Existence is the most perfect of realities. It is everywhere the ultimate actuality, since nothing has actuality except as it is. Hence existence is the actuality of all things, even of forms themselves. Hence existence is never related as receiver is related to content, but rather as content to receiver. When I speak of the existence of a man, say, or of a horse, or of anything else whatever, that existence is in the order of form, not of matter. It is the received perfection, not the subject which receives existence.

As I presently understand things, I have no problem in seeing existence as a received actuality or even as a received perfection, distinct from the subject receiving it. I further have no problem in seeing its existence as an actuality or perfection of any existent, since nothing is actual in any way unless it is existent and has existence.

I fail, however, to understand how the existence of any existent can be identified, not just as an actuality or perfection thereof, but as the actuality or perfection, as the “the” of “Hence existence is the actuality of all things” of the English translation at hand would have it. Since, however, the Latin original contains no definite article corresponding to that “the,” I’ll set this question aside.

I cannot, however, set aside the question that arises as I read, and reread:

Existence is … everywhere the ultimate actuality, since nothing has actuality except as it is.

Rewriting and reordering the statements of the argument so as to render it somewhat more perspicuous, we have:

All things having actuality are things having existence.

Therefore, the existence of anything having existence is its ultimate actuality.

There is, to say the least, a missing premise, one which I would like to see someone provide, for that premise would constitute the answer to my second question:

How is it that existence is the ultimate perfection or actuality of things and not simply their most basic perfection or actuality?

* Réginald Garrigou-Lagrange, O.P., Reality. A Synthesis of Thomistic Thought, translated by Patrick Cummins, O.S.B. (Ex Fontibus, 2006-2012)

** Réginald Garrigou-Lagrange, O.P., The One God. A Commentary on the First Part of St. Thomas’ Theological Summa, translated by Dom. Bede Rose, O.S.B., S.T.D. (Ex Fontibus, Undated)

*** Réginald Garrigou-Lagrange, O.P., God. His Existence and His Nature. A Thomistic Solution of Certain Agnostic Antinomies, translated from the fifth French edition by Dom. Bede Rose, O.S.B., D.D. (Lonely Peaks Reproductions, 2007)