"The good of the grace of one soul is greater than the good of the nature of the whole universe"
- St Thomas Aquinas Ia IIa, q.24, a. 3, ad 2

— A Commentary on the First Part of St Thomas' Theological Summa

by Reginald Garrigou-Lagrange, O. P.


Question 11: The Unity of God



State of the question. This article completes the idea of unity, inasmuch as it is compared with its opposite. The principal difficulty is enunciated in the fourth objection of this article, namely, that a vicious circle must be avoided in definitions, and there seems to be a vicious circle here; for if one is undivided being, it is opposed to the previously accepted notion of the divided, or to multitude. Thus multitude would come before and not after one, which is contrary to what was stated in the previous article,(15) and this would nullify the fourth way of proving God's existence.  

Reply. One is opposed to many but in various ways, inasmuch as one is considered the principle of number, or as it is convertible with being. For the one which is the principle of number, is opposed to multitude which is number, as the measure is to the thing measured; for number is multitude measured by one, as Aristotle says.(16) But the one which is convertible with being, is opposed to multitude by way of privation, as the undivided is to the thing divided. Thus we speak of a united kingdom as being against a kingdom that is divided.

The first kind of opposition referred to here is of the relative order, as between father and son; the other is privative. Aristotle mentions two other kinds of opposition; (17) namely, contradictory (as between a thing and its negation, between being and non-being, one and not one), and contrary (as between two opposite habits, for instance, between virtue and vice). Among these four kinds of opposition, the kind that is verified between transcendental unity and multitude is privative opposition.

Objection. But how is the principal difficulty to be answered? It is contended that if one is opposed to multitude, then it would follow that one comes after multitude, and is defined by it, as privation is by the want of form or perfection, as blindness is defined by privation of sight. But if unity is defined by privation of multitude, there is a vicious circle in definitions, for one is posited in the definition of multitude. Thus some define humility by its opposite, which is pride, as if it were a privation of pride; also pride is defined by humility, as if it were a privation of humility.

St. Thomas, in his reply to the fourth objection, concedes that "division is prior to unity, not absolutely in itself, but according to our way of apprehension. For we apprehend simple things by compound things; and hence we define a point to be what has no part, or the beginning of a line." Hence unity is defined by us as the privation of division, but not of multitude. Thus we conclude that one is prior to multitude, and is conceived as prior to multitude. In fact, as stated in this reply: what first comes to the mind is being; secondly, that this being is not that being, and thus we apprehend division; thirdly, comes the notion of one; fourthly, the notion of multitude. Hence we conclude that one is prior to multitude, although according to our way of apprehension it comes after division; for "we do not understand divided things to convey the idea of multitude except by the fact that we attribute unity to every part." Hence there is no circle in definitions. Moreover, as Cajetan observes, division is negation, which is logical being. Hence division is absolutely prior to unity in the intelligible order, but not in the natural order.

In the reply to the first objection, it is pointed out that multitude is the privation of unity and has its foundation in unity, because privation neither takes away entirely the existence or being of a thing, nor unity which is converted with being. For privation is the want of some perfection in a subject. Thus privation of being and of unity has its foundation in being and in unity. But this does not happen in the privation of special forms. Thus the privation of whiteness is not founded on whiteness, nor is the privation of sight on sight, but on the subject apt for sight.

It remains true, however, that opposition between one and many, inasmuch as, although many is one relatively and has its foundation in one, yet it is not one absolutely. What is many absolutely is one relatively, namely, according to either specific, generic, or analogical similarity. Also what is one absolutely, as man, is many relatively, by reason of its parts and accidents.

Reply to second objection. The other difficulty is solved, namely, that multitude is constituted by one, and therefore it is not opposed to multitude. In the reply it is stated that unities constitute multitude in so far as they have being, but not in so far as they are opposed to multitude. Thus the parts of a house make up the house by the fact that they are beings, not by the fact that they are "not houses," namely "not the whole." Every distinct part has a unity that is distinct from the unity of the whole.

The particular conclusions to be drawn from these first two articles are that unity is a property of being, inasmuch as one is undivided being, and that multitude by way of privation is opposed to this transcendental unity, but presupposes it, and this for two reasons: (1) because multitude is a plurality of unities; (2) because multitude results from the division of a being that is one either by unity of genus or of species or of quantity or of subject.

Index Top


15 Cf. ad 2um.

16. Metaph., Bk. X, chap. 1.

17. Ibid., Bk. V, chap. 10 (lect. 12 of St. Thomas' commentary).

18. Summa theol., Ia, q.3.



"Obedience is the true holocaust which we sacrifice to God on the altar of our hearts."

St Philip Neri

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"He who wishes to be perfectly obeyed, should give but few orders."

St Philip Neri

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"Shun too great a desire for knowledge, for in it there is much fretting and delusion. Intellectuals like to appear learned and to be called wise. Yet there are many things the knowledge of which does little or no good to the soul, and he who concerns himself about other things than those which lead to salvation is very unwise. "

Thomas á Kempis

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