Thomas Aquinas, Summa Theologiae

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 (Article 2). 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.

Articulus 3

Argumentum 1

Ad tertium sic proceditur. Videtur quod deo non conveniat vita.

Vivere enim dicuntur aliqua secundum quod movent seipsa, ut dictum est.

Sed deo non competit moveri. Ergo neque vivere.

Argumentum 2

Praeterea, in omnibus quae vivunt, est accipere aliquod vivendi principium, unde dicitur in II de anima, quod anima est viventis corporis causa et principium.

Sed deus non habet aliquod principium.

Ergo sibi non competit vivere.

Argumentum 3

Praeterea, principium vitae in rebus viventibus quae apud nos sunt, est anima vegetabilis, quae non est nisi in rebus corporalibus. Ergo rebus incorporalibus non competit vivere.

Sed Contra

Sed contra est quod dicitur in Psalmo LXXXIII, cor meum et caro mea exultaverunt in deum vivum.

Corpus

Respondeo dicendum quod vita maxime proprie in deo est.

Ad cuius evidentiam, considerandum est quod, cum vivere dicantur aliqua secundum quod operantur ex seipsis, et non quasi ab aliis mota; quanto perfectius competit hoc alicui, tanto perfectius in eo invenitur vita. In moventibus autem et motis tria per ordinem inveniuntur. Nam primo, finis movet agentem; agens vero principale est quod per suam formam agit; et hoc interdum agit per aliquod instrumentum, quod non agit ex virtute suae formae, sed ex virtute principalis agentis; cui instrumento competit sola executio actionis.

Inveniuntur igitur quaedam, quae movent seipsa, non habito respectu ad formam vel finem, quae inest eis a natura, sed solum quantum ad executionem motus, sed forma per quam agunt, et finis propter quem agunt, determinantur eis a natura. Et huiusmodi sunt plantae, quae secundum formam inditam eis a natura, movent seipsas secundum augmentum et decrementum. Quaedam vero ulterius movent seipsa, non solum habito respectu ad executionem motus, sed etiam quantum ad formam quae est principium motus, quam per se acquirunt. Et huiusmodi sunt animalia, quorum motus principium est forma non a natura indita, sed per sensum accepta. Unde quanto perfectiorem sensum habent, tanto perfectius movent seipsa. Nam ea quae non habent nisi sensum tactus, movent solum seipsa motu dilatationis et constrictionis, ut ostrea, parum excedentia motum plantae. Quae vero habent virtutem sensitivam perfectam, non solum ad cognoscendum coniuncta et tangentia, sed etiam ad cognoscendum distantia, movent seipsa in remotum motu processivo.

Sed quamvis huiusmodi animalia formam quae est principium motus, per sensum accipiant, non tamen per seipsa praestituunt sibi finem suae operationis, vel sui motus; sed est eis inditus a natura, cuius instinctu ad aliquid agendum moventur per formam sensu apprehensam. Unde supra talia animalia sunt illa quae movent seipsa, etiam habito respectu ad finem, quem sibi praestituunt.

Quod quidem non fit nisi per rationem et intellectum, cuius est cognoscere proportionem finis et eius quod est ad finem, et unum ordinare in alterum. Unde perfectior modus vivendi est eorum quae habent intellectum, haec enim perfectius movent seipsa. Et huius est signum, quod in uno et eodem homine virtus intellectiva movet potentias sensitivas; et potentiae sensitivae per suum imperium movent organa, quae exequuntur motum. Sicut etiam in artibus, videmus quod ars ad quam pertinet usus navis, scilicet ars gubernatoria, praecipit ei quae inducit formam navis, et haec praecipit illi quae habet executionem tantum, in disponendo materiam.

Sed quamvis intellectus noster ad aliqua se agat, tamen aliqua sunt ei praestituta a natura; sicut sunt prima principia, circa quae non potest aliter se habere, et ultimus finis, quem non potest non velle. Unde, licet quantum ad aliquid moveat se, tamen oportet quod quantum ad aliqua ab alio moveatur. Illud igitur cuius sua natura est ipsum eius intelligere, et cui id quod naturaliter habet, non determinatur ab alio, hoc est quod obtinet summum gradum vitae. Tale autem est deus.

Unde in deo maxime est vita. Unde philosophus, in XII metaphys., ostenso quod deus sit intelligens, concludit quod habeat vitam perfectissimam et sempiternam, quia intellectus eius est perfectissimus, et semper in actu.

Ad 1

Ad primum ergo dicendum quod, sicut dicitur in IX metaphys., duplex est actio, una, quae transit in exteriorem materiam, ut calefacere et secare; alia, quae manet in agente, ut intelligere, sentire et velle. Quarum haec est differentia, quia prima actio non est perfectio agentis quod movet, sed ipsius moti; secunda autem actio est perfectio agentis. Unde, quia motus est actus mobilis, secunda actio, inquantum est actus operantis, dicitur motus eius; ex hac similitudine, quod, sicut motus est actus mobilis, ita huiusmodi actio est actus agentis; licet motus sit actus imperfecti, scilicet existentis in potentia, huiusmodi autem actio est actus perfecti, idest existentis in actu, ut dicitur in III de anima.

Hoc igitur modo quo intelligere est motus, id quod se intelligit, dicitur se movere.

Et per hunc modum etiam Plato posuit quod deus movet seipsum, non eo modo quo motus est actus imperfecti.

Ad 2

Ad secundum dicendum quod, sicut deus est ipsum suum esse et suum intelligere, ita est suum vivere.

Et propter hoc, sic vivit, quod non habet vivendi principium.

Ad 3

Ad tertium dicendum quod vita in istis inferioribus recipitur in natura corruptibili, quae indiget et generatione ad conservationem speciei, et alimento ad conservationem individui. Et propter hoc, in istis inferioribus non invenitur vita sine anima vegetabili.

Sed hoc non habet locum in rebus incorruptibilibus.