Thomas Aquinas, Summa Theologiae

Objection 1: It seems that God is not the object of this science. For in every science, the nature of its object is presupposed. But this science cannot presuppose the essence of God, for Damascene says (De Fide Orth. i, iv): "It is impossible to define the essence of God." Therefore God is not the object of this science.

Objection 2: Further, whatever conclusions are reached in any science must be comprehended under the object of the science. But in Holy Writ we reach conclusions not only concerning God, but concerning many other things, such as creatures and human morality. Therefore God is not the object of this science.

On the contrary, The object of the science is that of which it principally treats. But in this science, the treatment is mainly about God; for it is called theology, as treating of God. Therefore God is the object of this science.

I answer that, God is the object of this science. The relation between a science and its object is the same as that between a habit or faculty and its object. Now properly speaking, the object of a faculty or habit is the thing under the aspect of which all things are referred to that faculty or habit, as man and stone are referred to the faculty of sight in that they are colored. Hence colored things are the proper objects of sight. But in sacred science, all things are treated of under the aspect of God: either because they are God Himself or because they refer to God as their beginning and end. Hence it follows that God is in very truth the object of this science. This is clear also from the principles of this science, namely, the articles of faith, for faith is about God. The object of the principles and of the whole science must be the same, since the whole science is contained virtually in its principles. Some, however, looking to what is treated of in this science, and not to the aspect under which it is treated, have asserted the object of this science to be something other than God---that is, either things and signs; or the works of salvation; or the whole Christ, as the head and members. Of all these things, in truth, we treat in this science, but so far as they have reference to God.

Reply to Objection 1: Although we cannot know in what consists the essence of God, nevertheless in this science we make use of His effects, either of nature or of grace, in place of a definition, in regard to whatever is treated of in this science concerning God; even as in some philosophical sciences we demonstrate something about a cause from its effect, by taking the effect in place of a definition of the cause.

Reply to Objection 2: Whatever other conclusions are reached in this sacred science are comprehended under God, not as parts or species or accidents but as in some way related to Him.

Articulus 7

Argumentum 1

Ad septimum sic proceditur. Videtur quod deus non sit subiectum huius scientiae. In qualibet enim scientia oportet supponere de subiecto quid est, secundum philosophum in I poster..

Sed haec scientia non supponit de deo quid est, dicit enim Damascenus, in deo quid est, dicere impossibile est.

Ergo deus non est subiectum huius scientiae.

Argumentum 2

Praeterea, omnia quae determinantur in aliqua scientia, comprehenduntur sub subiecto illius scientiae. Sed in sacra Scriptura determinatur de multis aliis quam de deo, puta de creaturis, et de moribus hominum.

Ergo deus non est subiectum huius scientiae.

Sed Contra

Sed contra, illud est subiectum scientiae, de quo est sermo in scientia. Sed in hac scientia fit sermo de deo, dicitur enim theologia, quasi sermo de deo.

Ergo deus est subiectum huius scientiae.

Corpus

Respondeo dicendum quod deus est subiectum huius scientiae.

Sic enim se habet subiectum ad scientiam, sicut obiectum ad potentiam vel habitum. Proprie autem illud assignatur obiectum alicuius potentiae vel habitus, sub cuius ratione omnia referuntur ad potentiam vel habitum, sicut homo et lapis referuntur ad visum inquantum sunt colorata, unde coloratum est proprium obiectum visus. Omnia autem pertractantur in sacra doctrina sub ratione dei, vel quia sunt ipse deus; vel quia habent ordinem ad deum, ut ad principium et finem. Unde sequitur quod deus vere sit subiectum huius scientiae. Quod etiam manifestum fit ex principiis huius scientiae, quae sunt articuli fidei, quae est de deo, idem autem est subiectum principiorum et totius scientiae, cum tota scientia virtute contineatur in principiis.

Quidam vero, attendentes ad ea quae in ista scientia tractantur, et non ad rationem secundum quam considerantur, assignaverunt aliter subiectum huius scientiae, vel res et signa; vel opera reparationis; vel totum christum, idest caput et membra. De omnibus enim istis tractatur in ista scientia, sed secundum ordinem ad deum.

Ad 1

Ad primum ergo dicendum quod, licet de deo non possimus scire quid est, utimur tamen eius effectu, in hac doctrina, vel naturae vel gratiae, loco definitionis, ad ea quae de deo in hac doctrina considerantur, sicut et in aliquibus scientiis philosophicis demonstratur aliquid de causa per effectum, accipiendo effectum loco definitionis causae.

Ad 2

Ad secundum dicendum quod omnia alia quae determinantur in sacra doctrina, comprehenduntur sub deo, non ut partes vel species vel accidentia, sed ut ordinata aliqualiter ad ipsum.