Summa summae S. Thomae sive compendium theologiae

[In establishing the existence of God there is a threefold rock equally to be avoided. — The first is that of those who affirm that no demonstration of the existence of God is to be undertaken, since it is to be held by faith alone and believed from revelation, concerning which we are certain from the authority of the human race. Such were the author of the work entitled Essai sur l'indifference en matiere de religion, and likewise Bautain, although led by another principle, who in his own apology addressed to the bishop of Strasbourg wrote: « I have the intimate persuasion, both as a Christian and as a philosopher, that reasoning alone cannot confer certitude on me concerning this primary truth, » namely, concerning the existence of God¹. These indeed bring into danger not only reason but faith as well. — The second, however, is that of those who say that at least no strict demonstration can be given concerning the same matter, because nothing prior to God is found from which, as from a principle, His existence may be proved. To be sure, most contend, and rightly, as it seems, that the existence of God cannot be established by the species of demonstration called a priori, or through the cause, or, as others say, from the antecedent, at least by a priority of order; nevertheless it is beyond doubt that the existence of God is proved a posteriori, which kind of demonstration others call a simultaneo, and St. Thomas uses this method, as we shall see presently. — The third, however, is that of those who deny that, by the very fact that this truth is established rationally, it can become an object of faith, that is, be believed at the same time by supernatural faith. Opposed to these is our Angelic Doctor, saying, in I Contra gentes, c. 4: « Since there is a twofold truth of divine intelligibles, one to which the inquiry of reason can attain, the other which exceeds the capacity of human reason, both are fittingly proposed by God to man for belief. But this must first be shown concerning that one [concerning the existence of God] which can be reached by the inquiry of reason; lest perhaps it should seem to someone that, since it can be had by reason, it was uselessly handed down to be believed by supernatural inspiration². » And the Holy Doctor accordingly explains « the inconveniences which would follow if the truth of this were left to be investigated by reason alone. » — Presently we shall report the dogmatic definition issued by the Church concerning the existence of God.]

Although that God exists is not per se known with respect to us, as we said in the preceding article, nevertheless that it is demonstrable through effects is established from Scripture itself, Rom. 1:20: The invisible things of God, says the Apostle, are clearly seen, being understood through the things that are made, his everlasting power also and divinity; so that they are inexcusable, etc.

I suppose that by the name of God there is understood by all, even by atheists themselves, that than which a greater and better cannot be thought, that is, an intelligent substance, supremely and infinitely perfect in every genus. Atheists say that this is impossible in reality, chiefly on account of that collection in it of all perfections, some of which are opposed to one another, for example immutability and liberty.

[1° It is of faith that God exists. 1° The Apostle says, Hebr. XI, 6: Without faith it is impossible to please God. For he that cometh to God must believe that He is, and is a rewarder to them that seek Him. Here the existence of God is proposed as an object of faith. — 2° Likewise, as of faith, the same truth was defined by the Vatican synod: « The holy catholic apostolic Roman Church believes and confesses that there is one true and living God, creator and Lord of heaven and earth, omnipotent, etc. » « If anyone shall have denied the one true God, creator and lord of things visible and invisible: let him be anathema³. » — This truth from the beginning of the Church holds the first place in the Symbol of faith.]

Secondly, St. Thomas proves that God exists by five principal arguments.

The first is proposed thus. — A first mover altogether immobile is given. But that is God. Therefore God is given. — As regards the minor, it is clear: because the first mover altogether immobile is most pure act, lacking all potentiality. For a thing is mobile insofar as it is in potency to that to which it is moved; hence that which is altogether immobile lacks all potentiality, and thus is most pure act. But most pure act contains every imaginable perfection; for if it lacked any, it would be in potency to it, and thus it would not be most pure act, and so it is that than which nothing greater and better can be thought, consequently God.

The major is proved. Everything that is moved is moved by another. But in movers per se subordinated there cannot be given a regress to infinity. Therefore there is given a first mover which is not moved and is altogether immobile. — The minor is evident, because movers are called per se subordinated when one mover, in order to move, needs the actual influx of a superior, so that the last does not move or act unless moved, and this by another, and so always, until one comes to the first. But since the infinite is impertransibile, one cannot in it come to the first; hence, if a regress to infinity be posited, there would be no motion nor action. — The major is proved. The same thing cannot be mover and moved in the same respect. Therefore everything that is moved is moved by another. — The antecedent is proved. The same thing cannot be in potency and in act with respect to the same thing: for to be in potency with respect to something is to tend toward it, and thus to lack it; but to be in act with respect to something is already to have it; but something cannot be had and not had at the same time. But if the same thing in the same respect were mover and moved, it would be in act and potency with respect to the same thing; for a thing is moved insofar as it is in potency, since to be moved is to be reduced from potency to act, and a thing moves insofar as it is in act; for to move is to effect act. Therefore.

The second argument. — There is given a first efficient cause of all things, altogether uncaused. But this is God. Therefore God is given.—The minor is evident from the preceding argument. — The major is proved. Everything that comes to be, comes to be by another; for nothing can effect itself, otherwise it would be before it was. But in efficient causes subordinated per se there cannot be given a process to infinity, as is clear from the preceding argument; nor even in causes subordinated per accidens, if God does not exist. Therefore. — The last part of the minor is proved. Causes are called subordinated per accidens when one cause has received from another the power of acting, yet does not need its actual influx in order actually to act, as is clear in the son who has received from the father the power of begetting, whose actual influx, however, he does not need in order to beget⁴.

Although, therefore, a process to infinity in causes thus subordinated per accidens is not repugnant, if a first agent be given outside the collection of infinite causes, it is nevertheless repugnant if this first agent is not given; but if it is not God, there is no first agent outside the whole collection. Therefore. — The antecedent is proved. Just as any cause is not from itself, but from another, so the whole collection is not from itself, but from another; because in all predicates that are not quantitative, of which sort is to be produced, the argument from the singulars to the whole holds good. But, as is supposed, no other causing thing is given outside the whole collection. Therefore it is repugnant for a process to infinity to be given, even in causes subordinated per accidens, if there is not a first agent outside the whole collection.

The third argument. — A necessary being is given, that is, one to which it belongs necessarily and from its own nature to exist. But such a being is God. Therefore God is given. — The minor is evident: 1° because a necessary being is a being a se, an unproduced being, independent, immutable, eternal, a being from which contingent things participate being; for what is through itself [or essentially] such, is the cause of the others which are such through accident, and thus a substantial being, spiritual, intelligent, the maker of all things. Therefore God. 2° A necessary being can be circumscribed by no limits in perfection. Therefore it is infinitely perfect. Therefore God. — The antecedent is proved. For by what can it be limited in perfection? Not by itself; for it is not the cause of itself, and if it were, it would confer upon itself every possible perfection; besides, what is necessary is only so much as it can be. Not by another, for it acknowledges nothing superior. Therefore.

The major is proved. If there were not given some necessary being, but all things in the nature of things were contingent and possible, then in point of fact no being would be given on the side of the thing ⁵. But the consequent is false. Therefore. — The consequence of the major is proved. Those things which state only possibility and contingency with respect to act cannot be reduced to that act except through a cause which necessarily contains that very act; thus, because water is in potency to heat, or is hot accidentally, it could never be heated unless there were given some being hot by its own nature, from which heat would flow into the water at least mediately or immediately. Therefore, if there is not given some necessary being to which it belongs by its own nature and necessarily to exist, in point of fact no being would be given on the side of the thing.

It is confirmed. Suppose that in fact there are no beings, as can happen if all things are contingent, for the contingent can be and not be; or at least imagine that there are none: from what will they have being, if there is no being existing necessarily? Not from themselves, for what is not cannot give itself that it be; not from another, for nothing else exists, as is supposed. Therefore they could not be. Therefore they would be and would not be possible: they would be, as is supposed, and they would not be, because there would be nothing from which they could have being. Therefore a necessary being must be admitted, from which all the rest have being.

The fourth argument. — There is given some being supremely perfect, supremely noble, being in the highest degree, which is the cause of every perfection in other things. But that is God. Therefore God is given. — The minor is clear from what has been said. — The major is proved. We see among beings that some are more or less beings, more or less perfect. But more and less are predicated of diverse things according as they approach more or less to something which is more such, and participate in it in diverse ways: just as that is hotter which approaches more to what is maximally hot and participates more in it. Therefore there is given in the nature of things some being supremely perfect, supremely noble, being in the highest degree, and indeed one which is the cause of other perfect things, whether efficient, or at least exemplary, inasmuch as from approach to or withdrawal from it, from greater or lesser participation, imitation, or falling away, the perfection of other things descends or is measured. For, according to the common axiom, the first in each genus is the cause of the rest which are of that genus, namely either an efficient or an exemplary cause.

Fifth argument. — There is given a highest provider and governor. But God is such. Therefore God is given. — The minor is evident, because by God we understand nothing other than the supreme divinity ruling and governing all things. — The major is proved. We see that some things which lack cognition operate not at random and by chance, but for an end; which is apparent from this, that they always or for the most part operate in the same way. The heavens, for example, are always moved in the same way; heavy things are borne always downward, light things always upward, etc. But things which do not have cognition do not tend toward an end unless directed by something cognizant and intelligent; just as an arrow would not reach the target unless it were directed by the archer. Therefore there is given a most wise governor and a certain supreme intelligence directing all things to their ends, which is God.

There is added a sixth argument akin to the preceding one, from the contemplation of this world, which is briefly set forth thus. — All the wondrous things that shine forth in this world, whether in heaven, or on earth, or in the sea, or in man himself alone, according to their structure, order, position, motion, disposition, beauty, variety, harmony in relation to their ends, cannot without madness be referred back to the chance concurrence of atoms, but must necessarily be ascribed to some supreme intelligence, the artificer and directress of all these things. But this is God, since by God all understand the supreme founder and ruler of the world. Therefore God is given. — The antecedent is proved. A work elaborated with exquisite skill, for example, a royal house, a clock, an elegant statue or painting, could not without madness be ascribed to chance or fortune, and not to a most skillful artificer. Therefore, a fortiori, the ordered and wondrous disposition of the whole world, indeed even of the human body alone, in which far more of art and industry shines forth than in the most exquisite works made by human art, cannot without madness be ascribed to the fortuitous concurrence of atoms, and not to a supreme intelligence. And indeed, if this world, wondrous with so great a variety of parts and with so fitting a disposition of all things to their ends, has been made by the fortuitous concurrence of atoms, I should like them to say why by this same fortuitous concurrence of atoms there has not at some time likewise been produced a clock or a royal palace, a statue or a painting, and other things which we see to be made by human art; or, as Tully says ⁶, why the poems of Homer are not made similarly from the fortuitous concurrence of letters, or a royal house from a fortuitous heap of timbers and stones, or painted panels from the fortuitous falling of colors upon them. — You will see this argument more fully expounded in the authors.