Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that the will is not moved to anything naturally. For the natural agent is condivided with the voluntary agent, as stated at the beginning of Phys. ii, 1. Therefore the will is not moved to anything naturally.

Objection 2: Further, that which is natural is in a thing always: as "being hot" is in fire. But no movement is always in the will. Therefore no movement is natural to the will.

Objection 3: Further, nature is determinate to one thing: whereas the will is referred to opposites. Therefore the will wills nothing naturally.

On the contrary, The movement of the will follows the movement of the intellect. But the intellect understands some things naturally. Therefore the will, too, wills some things naturally.

I answer that, As Boethius says (De Duabus Nat.) and the Philosopher also (Metaph. v, 4) the word "nature" is used in a manifold sense. For sometimes it stands for the intrinsic principle in movable things. In this sense nature is either matter or the material form, as stated in Phys. ii, 1. In another sense nature stands for any substance, or even for any being. And in this sense, that is said to be natural to a thing which befits it in respect of its substance. And this is that which of itself is in a thing. Now all things that do not of themselves belong to the thing in which they are, are reduced to something which belongs of itself to that thing, as to their principle. Wherefore, taking nature in this sense, it is necessary that the principle of whatever belongs to a thing, be a natural principle. This is evident in regard to the intellect: for the principles of intellectual knowledge are naturally known. In like manner the principle of voluntary movements must be something naturally willed.

Now this is good in general, to which the will tends naturally, as does each power to its object; and again it is the last end, which stands in the same relation to things appetible, as the first principles of demonstrations to things intelligible: and, speaking generally, it is all those things which belong to the willer according to his nature. For it is not only things pertaining to the will that the will desires, but also that which pertains to each power, and to the entire man. Wherefore man wills naturally not only the object of the will, but also other things that are appropriate to the other powers; such as the knowledge of truth, which befits the intellect; and to be and to live and other like things which regard the natural well-being; all of which are included in the object of the will, as so many particular goods.

Reply to Objection 1: The will is distinguished from nature as one kind of cause from another; for some things happen naturally and some are done voluntarily. There is, however, another manner of causing that is proper to the will, which is mistress of its act, besides the manner proper to nature, which is determinate to one thing. But since the will is founded on some nature, it is necessary that the movement proper to nature be shared by the will, to some extent: just as what belongs to a previous cause is shared by a subsequent cause. Because in every thing, being itself, which is from nature, precedes volition, which is from the will. And hence it is that the will wills something naturally.

Reply to Objection 2: In the case of natural things, that which is natural, as a result of the form only, is always in them actually, as heat is in fire. But that which is natural as a result of matter, is not always in them actually, but sometimes only in potentiality: because form is act, whereas matter is potentiality. Now movement is "the act of that which is in potentiality" (Aristotle, Phys. iii, 1). Wherefore that which belongs to, or results from, movement, in regard to natural things, is not always in them. Thus fire does not always move upwards, but only when it is outside its own place. And in like manner it is not necessary that the will (which is reduced from potentiality to act, when it wills something), should always be in the act of volition; but only when it is in a certain determinate disposition. But God's will, which is pure act, is always in the act of volition.

Reply to Objection 3: To every nature there is one thing corresponding, proportionate, however, to that nature. For to nature considered as a genus, there corresponds something one generically; and to nature as species there corresponds something one specifically; and to the individualized nature there corresponds some one individual. Since, therefore, the will is an immaterial power like the intellect, some one general thing corresponds to it, naturally which is the good; just as to the intellect there corresponds some one general thing, which is the true, or being, or "what a thing is." And under good in general are included many particular goods, to none of which is the will determined.

Articulus 1

Argumentum 1

Ad primum sic proceditur. Videtur quod voluntas non moveatur ad aliquid naturaliter.

Agens enim naturale dividitur contra agens voluntarium, ut patet in principio II physic..

Non ergo voluntas ad aliquid naturaliter movetur.

Argumentum 2

Praeterea, id quod est naturale, inest alicui semper; sicut igni esse calidum. Sed nullus motus inest voluntati semper.

Ergo nullus motus est naturalis voluntati.

Argumentum 3

Praeterea, natura est determinata ad unum. Sed voluntas se habet ad opposita. Ergo voluntas nihil naturaliter vult.

Sed Contra

Sed contra est quod motus voluntatis sequitur actum intellectus. Sed intellectus aliqua intelligit naturaliter.

Ergo et voluntas aliqua vult naturaliter.

Corpus

Respondeo dicendum quod, sicut boetius dicit in libro de duabus naturis, et philosophus in V metaphys., natura dicitur multipliciter.

Quandoque enim dicitur principium intrinsecum in rebus mobilibus.

Et talis natura est vel materia, vel forma materialis, ut patet ex II physic..

Alio modo dicitur natura quaelibet substantia, vel etiam quodlibet ens. Et secundum hoc, illud dicitur esse naturale rei, quod convenit ei secundum suam substantiam.

Et hoc est quod per se inest rei. In omnibus autem, ea quae non per se insunt, reducuntur in aliquid quod per se inest, sicut in principium. Et ideo necesse est quod, hoc modo accipiendo naturam, semper principium in his quae conveniunt rei, sit naturale. Et hoc manifeste apparet in intellectu, nam principia intellectualis cognitionis sunt naturaliter nota. Similiter etiam principium motuum voluntariorum oportet esse aliquid naturaliter volitum. Hoc autem est bonum in communi, in quod voluntas naturaliter tendit, sicut etiam quaelibet potentia in suum obiectum, et etiam ipse finis ultimus, qui hoc modo se habet in appetibilibus, sicut prima principia demonstrationum in intelligibilibus, et universaliter omnia illa quae conveniunt volenti secundum suam naturam. Non enim per voluntatem appetimus solum ea quae pertinent ad potentiam voluntatis; sed etiam ea quae pertinent ad singulas potentias, et ad totum hominem. Unde naturaliter homo vult non solum obiectum voluntatis, sed etiam alia quae conveniunt aliis potentiis, ut cognitionem veri, quae convenit intellectui; et esse et vivere et alia huiusmodi, quae respiciunt consistentiam naturalem; quae omnia comprehenduntur sub obiecto voluntatis, sicut quadam particularia bona.

Ad 1

Ad primum ergo dicendum quod voluntas dividitur contra naturam, sicut una causa contra aliam, quaedam enim fiunt naturaliter, et quaedam fiunt voluntarie. Est autem alius modus causandi proprius voluntati, quae est domina sui actus, praeter modum qui convenit naturae, quae est determinata ad unum. Sed quia voluntas in aliqua natura fundatur, necesse est quod motus proprius naturae, quantum ad aliquid, participetur in voluntate, sicut quod est prioris causae, participatur a posteriori. Est enim prius in unaquaque re ipsum esse, quod est per naturam, quam velle, quod est per voluntatem. Et inde est quod voluntas naturaliter aliquid vult.

Ad 2

Ad secundum dicendum quod in rebus naturalibus id quod est naturale quasi consequens formam tantum, semper actu inest, sicut calidum igni. Quod autem est naturale sicut consequens materiam, non semper actu inest, sed quandoque secundum potentiam tantum.

Nam forma est actus, materia vero potentia. Motus autem est actus existentis in potentia. Et ideo illa quae pertinent ad motum, vel quae consequuntur motum, in rebus naturalibus, non semper insunt, sicut ignis non semper movetur sursum, sed quando est extra locum suum. Et similiter non oportet quod voluntas, quae de potentia in actum reducitur dum aliquid vult, semper actu velit, sed solum quando est in aliqua dispositione determinata.

Voluntas autem dei, quae est actus purus, semper est in actu volendi.

Ad 3

Ad tertium dicendum quod naturae semper respondet unum, proportionatum tamen naturae. Naturae enim in genere, respondet aliquid unum in genere; et naturae in specie acceptae, respondet unum in specie; naturae autem individuatae respondet aliquid unum individuale. Cum igitur voluntas sit quaedam vis immaterialis sicut et intellectus, respondet sibi naturaliter aliquod unum commune, scilicet bonum, sicut etiam intellectui aliquod unum commune, scilicet verum, vel ens, vel quod quid est.

Sub bono autem communi multa particularia bona continentur, ad quorum nullum voluntas determinatur.