1 Objection 1: It seems that God does not understand Himself. For it is said by the Philosopher De Causis), Every knower who knows his own essence, returns completely to his own essence. But God does not go out from His own essence, nor is He moved at all; thus He cannot return to His own essence. Therefore He does not know His own essence.
1 Ad secundum sic proceditur. Videtur quod Deus non intelligat se. Dicitur enim in libro de causis, quod omnis sciens qui scit suam essentiam, est rediens ad essentiam suam reditione completa. Sed Deus non exit extra essentiam suam, nec aliquo modo movetur, et sic non competit sibi redire ad essentiam suam. Ergo ipse non est sciens essentiam suam.
2 Objection 2: Further, to understand is a kind of passion and movement, as the Philosopher says De Anima iii); and knowledge also is a kind of assimilation to the object known; and the thing known is the perfection of the knower. But nothing is moved, or suffers, or is made perfect by itself, nor, as Hilary says De Trin. iii), is a thing its own likeness. Therefore God does not understand Himself.
2 Praeterea, intelligere est quoddam pati et moveri, ut dicitur in III de anima, scientia etiam est assimilatio ad rem scitam, et scitum etiam est perfectio scientis. Sed nihil movetur, vel patitur, vel perficitur a seipso; neque similitudo sibi est, ut Hilarius dicit. Ergo Deus non est sciens seipsum.
3 Objection 3: Further, we are like to God chiefly in our intellect, because we are the image of God in our mind, as Augustine says Gen. ad lit. vi). But our intellect understands itself, only as it understands other things, as is said in De Anima iii. Therefore God understands Himself only so far perchance as He understands other things.
3 Praeterea, praecipue Deo sumus similes secundum intellectum, quia secundum mentem sumus ad imaginem Dei, ut dicit Augustinus. Sed intellectus noster non intelligit se, nisi sicut intelligit alia, ut dicitur in III de anima. Ergo nec Deus intelligit se, nisi forte intelligendo alia.
4 On the contrary, It is written: The things that are of God no man knoweth, but the Spirit of God 1 Cor. 2, 11).
4 Sed contra est quod dicitur I ad Cor. II, quae sunt Dei, nemo novit nisi spiritus Dei.
5 I answer that, God understands Himself through Himself. In proof whereof it must be known that although in operations which pass to an external effect, the object of the operation, which is taken as the term, exists outside the operator; nevertheless in operations that remain in the operator, the object signified as the term of operation, resides in the operator; and accordingly as it is in the operator, the operation is actual. Hence the Philosopher says De Anima iii) that the sensible in act is sense in act, and the intelligible in act is intellect in act. For the reason why we actually feel or know a thing is because our intellect or sense is actually informed by the sensible or intelligible species. And because of this only, it follows that sense or intellect is distinct from the sensible or intelligible object, since both are in potentiality. Since therefore God has nothing in Him of potentiality, but is pure act, His intellect and its object are altogether the same; so that He neither is without the intelligible species, as is the case with our intellect when it understands potentially; nor does the intelligible species differ from the substance of the divine intellect, as it differs in our intellect when it understands actually; but the intelligible species itself is the divine intellect itself, and thus God understands Himself through Himself.
5 Respondeo dicendum quod Deus se per seipsum intelligit. Ad cuius evidentiam, sciendum est quod, licet in operationibus quae transeunt in exteriorem effectum, obiectum operationis, quod significatur ut terminus, sit aliquid extra operantem; tamen in operationibus quae sunt in operante, obiectum quod significatur ut terminus operationis, est in ipso operante; et secundum quod est in eo, sic est operatio in actu. Unde dicitur in libro de anima, quod sensibile in actu est sensus in actu, et intelligibile in actu est intellectus in actu. Ex hoc enim aliquid in actu sentimus vel intelligimus, quod intellectus noster vel sensus informatur in actu per speciem sensibilis vel intelligibilis. Et secundum hoc tantum sensus vel intellectus aliud est a sensibili vel intelligibili, quia utrumque est in potentia. Cum igitur Deus nihil potentialitatis habeat, sed sit actus purus, oportet quod in eo intellectus et intellectum sint idem omnibus modis, ita scilicet, ut neque careat specie intelligibili, sicut intellectus noster cum intelligit in potentia; neque species intelligibilis sit aliud a substantia intellectus divini, sicut accidit in intellectu nostro, cum est actu intelligens; sed ipsa species intelligibilis est ipse intellectus divinus. Et sic seipsum per seipsum intelligit.
6 Reply to Objection 1: Return to its own essence means only that a thing subsists in itself. Inasmuch as the form perfects the matter by giving it existence, it is in a certain way diffused in it; and it returns to itself inasmuch as it has existence in itself. Therefore those cognitive faculties which are not subsisting, but are the acts of organs, do not know themselves, as in the case of each of the senses; whereas those cognitive faculties which are subsisting, know themselves; hence it is said in De Causis that, whoever knows his essence returns to it. Now it supremely belongs to God to be self-subsisting. Hence according to this mode of speaking, He supremely returns to His own essence, and knows Himself.
6 Ad primum ergo dicendum quod redire ad essentiam suam nihil aliud est quam rem subsistere in seipsa. Forma enim, inquantum perficit materiam dando ei esse, quodammodo supra ipsam effunditur, inquantum vero in seipsa habet esse, in seipsam redit. Virtutes igitur cognoscitivae quae non sunt subsistentes, sed actus aliquorum organorum, non cognoscunt seipsas; sicut patet in singulis sensibus. Sed virtutes cognoscitivae per se subsistentes, cognoscunt seipsas. Et propter hoc dicitur in libro de causis, quod sciens essentiam suam, redit ad essentiam suam. Per se autem subsistere maxime convenit Deo. Unde secundum hunc modum loquendi, ipse est maxime rediens ad essentiam suam, et cognoscens seipsum.
7 Reply to Objection 2: Movement and passion are taken equivocally, according as to understand is described as a kind of movement or passion, as stated in De Anima iii. For to understand is not a movement that is an act of something imperfect passing from one to another, but it is an act, existing in the agent itself, of something perfect. Likewise that the intellect is perfected by the intelligible object, that is, is assimilated to it, this belongs to an intellect which is sometimes in potentiality; because the fact of its being in a state of potentiality makes it differ from the intelligible object and assimilates it thereto through the intelligible species, which is the likeness of the thing understood, and makes it to be perfected thereby, as potentiality is perfected by act. On the other hand, the divine intellect, which is no way in potentiality, is not perfected by the intelligible object, nor is it assimilated thereto, but is its own perfection, and its own intelligible object.
7 Ad secundum dicendum quod moveri et pati sumuntur aequivoce secundum quod intelligere dicitur esse quoddam moveri vel pati, ut dicitur in III de anima. Non enim intelligere est motus qui est actus imperfecti, qui est ab alio in aliud, sed actus perfecti, existens in ipso agente. Similiter etiam quod intellectus perficiatur ab intelligibili vel assimiletur ei, hoc convenit intellectui qui quandoque est in potentia, quia per hoc quod est in potentia, differt ab intelligibili, et assimilatur ei per speciem intelligibilem, quae est similitudo rei intellectae; et perficitur per ipsam, sicut potentia per actum. Sed intellectus divinus, qui nullo modo est in potentia, non perficitur per intelligibile, neque assimilatur ei, sed est sua perfectio et suum intelligibile.
8 Reply to Objection 3: Existence in nature does not belong to primary matter, which is a potentiality, unless it is reduced to act by a form. Now our passive intellect has the same relation to intelligible objects as primary matter has to natural things; for it is in potentiality as regards intelligible objects, just as primary matter is to natural things. Hence our passive intellect can be exercised concerning intelligible objects only so far as it is perfected by the intelligible species of something; and in that way it understands itself by an intelligible species, as it understands other things: for it is manifest that by knowing the intelligible object it understands also its own act of understanding, and by this act knows the intellectual faculty. But God is a pure act in the order of existence, as also in the order of intelligible objects; therefore He understands Himself through Himself.
8 Ad tertium dicendum quod esse naturale non est materiae primae, quae est in potentia, nisi secundum quod est reducta in actum per formam. Intellectus autem noster possibilis se habet in ordine intelligibilium, sicut materia prima in ordine rerum naturalium, eo quod est in potentia ad intelligibilia, sicut materia prima ad naturalia. Unde intellectus noster possibilis non potest habere intelligibilem operationem, nisi inquantum perficitur per speciem intelligibilem alicuius. Et sic intelligit seipsum per speciem intelligibilem, sicut et alia, manifestum est enim quod ex eo quod cognoscit intelligibile, intelligit ipsum suum intelligere, et per actum cognoscit potentiam intellectivam. Deus autem est sicut actus purus tam in ordine existentium, quam in ordine intelligibilium, et ideo per seipsum, seipsum intelligit.