Summa Theologica, by St. Thomas Aquinas, , at sacred-texts.com
Since to understand belongs to living beings, after considering the divine knowledge and intellect, we must consider the divine life. About this, four points of inquiry arise:
(1) To whom does it belong to live?
(2) What is life?
(3) Whether life is properly attributed to God?
(4) Whether all things in God are life?
Objection 1: It seems that to live belongs to all natural things. For the Philosopher says (Phys. viii, 1) that "Movement is like a kind of life possessed by all things existing in nature." But all natural things participate in movement. Therefore all natural things partake of life.
Objection 2: Further, plants are said to live, inasmuch as they in themselves a principle of movement of growth and decay. But local movement is naturally more perfect than, and prior to, movement of growth and decay, as the Philosopher shows (Phys. viii, 56,57). Since then, all natural bodies have in themselves some principle of local movement, it seems that all natural bodies live.
Objection 3: Further, amongst natural bodies the elements are the less perfect. Yet life is attributed to them, for we speak of "living waters." Much more, therefore, have other natural bodies life.
On the contrary, Dionysius says (Div. Nom. vi, 1) that "The last echo of life is heard in the plants," whereby it is inferred that their life is life in its lowest degree. But inanimate bodies are inferior to plants. Therefore they have not life.
I answer that, We can gather to what things life belongs, and to what it does not, from such things as manifestly possess life. Now life manifestly belongs to animals, for it said in De Vegetab. i [*De Plantis i, 1] that in animals life is manifest. We must, therefore, distinguish living from lifeless things, by comparing them to that by reason of which animals are said to live: and this it is in which life is manifested first and remains last. We say then that an animal begins to live when it begins to move of itself: and as long as such movement appears in it, so long as it is considered to be alive. When it no longer has any movement of itself, but is only moved by another power, then its life is said to fail, and the animal to be dead. Whereby it is clear that those things are properly called living that move themselves by some kind of movement, whether it be movement properly so called, as the act of an imperfect being, i.e. of a thing in potentiality, is called movement; or movement in a more general sense, as when said of the act of a perfect thing, as understanding and feeling are called movement. Accordingly all things are said to be alive that determine themselves to movement or operation of any kind: whereas those things that cannot by their nature do so, cannot be called living, unless by a similitude.
Reply to Objection 1: These words of the Philosopher may be understood either of the first movement, namely, that of the celestial bodies, or of the movement in its general sense. In either way is movement called the life, as it were, of natural bodies, speaking by a similitude, and not attributing it to them as their property. The movement of the heavens is in the universe of corporeal natures as the movement of the heart, whereby life is preserved, is in animals. Similarly also every natural movement in respect to natural things has a certain similitude to the operations of life. Hence, if the whole corporeal universe were one animal, so that its movement came from an "intrinsic moving force," as some in fact have held, in that case movement would really be the life of all natural bodies.
Reply to Objection 2: To bodies, whether heavy or light, movement does not belong, except in so far as they are displaced from their natural conditions, and are out of their proper place; for when they are in the place that is proper and natural to them, then they are at rest. Plants and other living things move with vital movement, in accordance with the disposition of their nature, but not by approaching thereto, or by receding from it, for in so far as they recede from such movement, so far do they recede from their natural disposition. Heavy and light bodies are moved by an extrinsic force, either generating them and giving them form, or removing obstacles from their way. They do not therefore move themselves, as do living bodies.
Reply to Objection 3: Waters are called living that have a continuous current: for standing waters, that are not connected with a continually flowing source, are called dead, as in cisterns and ponds. This is merely a similitude, inasmuch as the movement they are seen to possess makes them look as if they were alive. Yet this is not life in them in its real sense, since this movement of theirs is not from themselves but from the cause that generates them. The same is the case with the movement of other heavy and light bodies.
Objection 1: It seems that life is an operation. For nothing is divided except into parts of the same genus. But life is divided by certain operations, as is clear from the Philosopher (De Anima ii, 13), who distinguishes four kinds of life, namely, nourishment, sensation, local movement and understanding. Therefore life is an operation.
Objection 2: Further, the active life is said to be different from the contemplative. But the contemplative is only distinguished from the active by certain operations. Therefore life is an operation.
Objection 3: Further, to know God is an operation. But this is life, as is clear from the words of Jn. 18:3, "Now this is eternal life, that they may know Thee, the only true God." Therefore life is an operation.
On the contrary, The Philosopher says (De Anima ii, 37), "In living things, to live is to be."
I answer that, As is clear from what has been said (Q, A), our intellect, which takes cognizance of the essence of a thing as its proper object, gains knowledge from sense, of which the proper objects are external accidents. Hence from external appearances we come to the knowledge of the essence of things. And because we name a thing in accordance with our knowledge of it, as is clear from what has already been said (Q, A), so from external properties names are often imposed to signify essences. Hence such names are sometimes taken strictly to denote the essence itself, the signification of which is their principal object; but sometimes, and less strictly, to denote the properties by reason of which they are imposed. And so we see that the word "body" is used to denote a genus of substances from the fact of their possessing three dimensions: and is sometimes taken to denote the dimensions themselves; in which sense body is said to be a species of quantity. The same must be said of life. The name is given from a certain external appearance, namely, self-movement, yet not precisely to signify this, but rather a substance to which self-movement and the application of itself to any kind of operation, belong naturally. To live, accordingly, is nothing else than to exist in this or that nature; and life signifies this, though in the abstract, just as the word "running" denotes "to run" in the abstract.
Hence "living" is not an accidental but an essential predicate. Sometimes, however, life is used less properly for the operations from which its name is taken, and thus the Philosopher says (Ethic. ix, 9) that to live is principally to sense or to understand.
Reply to Objection 1: The Philosopher here takes "to live" to mean an operation of life. Or it would be better to say that sensation and intelligence and the like, are sometimes taken for the operations, sometimes for the existence itself of the operator. For he says (Ethic. ix, 9) that to live is to sense or to understand---in other words, to have a nature capable of sensation or understanding. Thus, then, he distinguishes life by the four operations mentioned. For in this lower world there are four kinds of living things. It is the nature of some to be capable of nothing more than taking nourishment, and, as a consequence, of growing and generating. Others are able, in addition, to sense, as we see in the case of shellfish and other animals without movement. Others have the further power of moving from place to place, as perfect animals, such as quadrupeds, and birds, and so on. Others, as man, have the still higher faculty of understanding.
Reply to Objection 2: By vital operations are meant those whose principles are within the operator, and in virtue of which the operator produces such operations of itself. It happens that there exist in men not merely such natural principles of certain operations as are their natural powers, but something over and above these, such as habits inclining them like a second nature to particular kinds of operations, so that the operations become sources of pleasure. Thus, as by a similitude, any kind of work in which a man takes delight, so that his bent is towards it, his time spent in it, and his whole life ordered with a view to it, is said to be the life of that man. Hence some are said to lead to life of self-indulgence, others a life of virtue. In this way the contemplative life is distinguished from the active, and thus to know God is said to be life eternal.
Wherefore the Reply to the Third Objection is clear.
Objection 1: It seems that life is not properly attributed to God. For things are said to live inasmuch as they move themselves, as previously stated (A). But movement does not belong to God. Neither therefore does life.
Objection 2: Further, in all living things we must needs suppose some principle of life. Hence it is said by the Philosopher (De Anima ii, 4) that "the soul is the cause and principle of the living body." But God has no principle. Therefore life cannot be attributed to Him.
Objection 3: Further, the principle of life in the living things that exist among us is the vegetative soul. But this exists only in corporeal things. Therefore life cannot be attributed to incorporeal things.
On the contrary, It is said (Ps. 83:3): "My heart and my flesh have rejoiced in the living God."
I answer that, Life is in the highest degree properly in God. In proof of which it must be considered that since a thing is said to live in so far as it operates of itself and not as moved by another, the more perfectly this power is found in anything, the more perfect is the life of that thing. In things that move and are moved, a threefold order is found. In the first place, the end moves the agent: and the principal agent is that which acts through its form, and sometimes it does so through some instrument that acts by virtue not of its own form, but of the principal agent, and does no more than execute the action. Accordingly there are things that move themselves, not in respect of any form or end naturally inherent in them, but only in respect of the executing of the movement; the form by which they act, and the end of the action being alike determined for them by their nature. Of this kind are plants, which move themselves according to their inherent nature, with regard only to executing the movements of growth and decay.
Other things have self-movement in a higher degree, that is, not only with regard to executing the movement, but even as regards to the form, the principle of movement, which form they acquire of themselves. Of this kind are animals, in which the principle of movement is not a naturally implanted form; but one received through sense. Hence the more perfect is their sense, the more perfect is their power of self-movement. Such as have only the sense of touch, as shellfish, move only with the motion of expansion and contraction; and thus their movement hardly exceeds that of plants. Whereas such as have the sensitive power in perfection, so as to recognize not only connection and touch, but also objects apart from themselves, can move themselves to a distance by progressive movement. Yet although animals of the latter kind receive through sense the form that is the principle of their movement, nevertheless they cannot of themselves propose to themselves the end of their operation, or movement; for this has been implanted in them by nature; and by natural instinct they are moved to any action through the form apprehended by sense. Hence such animals as move themselves in respect to an end they themselves propose are superior to these. This can only be done by reason and intellect; whose province it is to know the proportion between the end and the means to that end, and duly coordinate them. Hence a more perfect degree of life is that of intelligible beings; for their power of self-movement is more perfect. This is shown by the fact that in one and the same man the intellectual faculty moves the sensitive powers; and these by their command move the organs of movement. Thus in the arts we see that the art of using a ship, i.e. the art of navigation, rules the art of ship-designing; and this in its turn rules the art that is only concerned with preparing the material for the ship.
But although our intellect moves itself to some things, yet others are supplied by nature, as are first principles, which it cannot doubt; and the last end, which it cannot but will. Hence, although with respect to some things it moves itself, yet with regard to other things it must be moved by another. Wherefore that being whose act of understanding is its very nature, and which, in what it naturally possesses, is not determined by another, must have life in the most perfect degree. Such is God; and hence in Him principally is life. From this the Philosopher concludes (Metaph. xii, 51), after showing God to be intelligent, that God has life most perfect and eternal, since His intellect is most perfect and always in act.
Reply to Objection 1: As stated in Metaph. ix, 16, action is twofold. Actions of one kind pass out to external matter, as to heat or to cut; whilst actions of the other kind remain in the agent, as to understand, to sense and to will. The difference between them is this, that the former action is the perfection not of the agent that moves, but of the thing moved; whereas the latter action is the perfection of the agent. Hence, because movement is an act of the thing in movement, the latter action, in so far as it is the act of the operator, is called its movement, by this similitude, that as movement is an act of the thing moved, so an act of this kind is the act of the agent, although movement is an act of the imperfect, that is, of what is in potentiality; while this kind of act is an act of the perfect, that is to say, of what is in act as stated in De Anima iii, 28. In the sense, therefore, in which understanding is movement, that which understands itself is said to move itself. It is in this sense that Plato also taught that God moves Himself; not in the sense in which movement is an act of the imperfect.
Reply to Objection 2: As God is His own very existence and understanding, so is He His own life; and therefore He so lives that He has not principle of life.
Reply to Objection 3: Life in this lower world is bestowed on a corruptible nature, that needs generation to preserve the species, and nourishment to preserve the individual. For this reason life is not found here below apart from a vegetative soul: but this does not hold good with incorruptible natures.
Objection 1: It seems that not all things are life in God. For it is said (Acts 17:28), "In Him we live, and move, and be." But not all things in God are movement. Therefore not all things are life in Him.
Objection 2: Further, all things are in God as their first model. But things modelled ought to conform to the model. Since, then, not all things have life in themselves, it seems that not all things are life in God.
Objection 3: Further, as Augustine says (De Vera Relig. 29), a living substance is better than a substance that does not live. If, therefore, things which in themselves have not life, are life in God, it seems that things exist more truly in God than themselves. But this appears to be false; since in themselves they exist actually, but in God potentially.
Objection 4: Further, just as good things and things made in time are known by God, so are bad things, and things that God can make, but never will be made. If, therefore, all things are life in God, inasmuch as known by Him, it seems that even bad things and things that will never be made are life in God, as known by Him, and this appears inadmissible.
On the contrary, (John 1:3, 4), it is said, "What was made, in Him was life." But all things were made, except God. Therefore all things are life in God.
I answer that, In God to live is to understand, as before stated (A). In God intellect, the thing understood, and the act of understanding, are one and the same. Hence whatever is in God as understood is the very living or life of God. Now, wherefore, since all things that have been made by God are in Him as things understood, it follows that all things in Him are the divine life itself.
Reply to Objection 1: Creatures are said to be in God in a twofold sense. In one way, so far are they are held together and preserved by the divine power; even as we say that things that are in our power are in us. And creatures are thus said to be in God, even as they exist in their own natures. In this sense we must understand the words of the Apostle when he says, "In Him we live, move, and be"; since our being, living, and moving are themselves caused by God. In another sense things are said to be in God, as in Him who knows them, in which sense they are in God through their proper ideas, which in God are not distinct from the divine essence. Hence things as they are in God are the divine essence. And since the divine essence is life and not movement, it follows that things existing in God in this manner are not movement, but life.
Reply to Objection 2: The thing modelled must be like the model according to the form, not the mode of being. For sometimes the form has being of another kind in the model from that which it has in the thing modelled. Thus the form of a house has in the mind of the architect immaterial and intelligible being; but in the house that exists outside his mind, material and sensible being. Hence the ideas of things, though not existing in themselves, are life in the divine mind, as having a divine existence in that mind.
Reply to Objection 3: If form only, and not matter, belonged to natural things, then in all respects natural things would exist more truly in the divine mind, by the ideas of them, than in themselves. For which reason, in fact, Plato held that the "separate" man was the true man; and that man as he exists in matter, is man only by participation. But since matter enters into the being of natural things, we must say that those things have simply being in the divine mind more truly than in themselves, because in that mind they have an uncreated being, but in themselves a created being: whereas this particular being, a man, or horse, for example, has this being more truly in its own nature than in the divine mind, because it belongs to human nature to be material, which, as existing in the divine mind, it is not. Even so a house has nobler being in the architect's mind than in matter; yet a material house is called a house more truly than the one which exists in the mind; since the former is actual, the latter only potential.
Reply to Objection 4: Although bad things are in God's knowledge, as being comprised under that knowledge, yet they are not in God as created by Him, or preserved by Him, or as having their type in Him. They are known by God through the types of good things. Hence it cannot be said that bad things are life in God. Those things that are not in time may be called life in God in so far as life means understanding only, and inasmuch as they are understood by God; but not in so far as life implies a principle of operation.