Summa contra Gentiles2.4 Chapter IV. That the Philosopher and the theologian treat of creatures in different ways

Now it is evident from what has been said that the teaching of the Christian faith treats of creatures in so far as they reflect a certain likeness of God, and forasmuch as error concerning them leads to error about God. And so they are viewed from a different point by the aforesaid teaching, and by that of human philosophy. For human philosophy considers them as such; wherefore find that the different parts of philosophy correspond to the different genera of things. On the other hand the Christian faith does not consider them as such, for instance it considers fire not as such, but as representing the sublimity of God, and as being directed to Him in any way whatsoever. For as it is stated (Ecclus. xlii. i, 17), Full of the glory of the Lord is His work. Hath not the Lord made the saints to declare all His wonderful works? Hence also the philosopher and the believer consider different matters about creatures. Eor the philosopher considers such things as belong to them by their own nature: for instance that fire tends upwards. Whereas the believer considers about creatures only such things as belong to them in respect of their relation to God: for instance that they are created by God, are subject to God, and so forth.

Wherefore it argues not imperfection in the teaching of faith, if it overlooks many properties of things, such as the shape of the heavens, and the quality of its movement: since neither does the physicist consider the same characters of a line as the geometrician, but only such as are accidental thereto, as the term of a natural body.

Any matters, however, that the philosopher and the believer in common consider about creatures, are delivered through different principles on the one hand and on the other. For the philosopher takes his argument from the proper causes of things: whereas the believer has recourse to the First Cause, for instance because it has been thus delivered by God, or because it conduces to God's glory, or because God's power is infinite. Hence (the teaching of faith) should be called the greatest wisdom, since it considers the highest cause, according to the saying of Deut. iv. 6: For this is your wisdom and understanding in the sight of nations. Wherefore human philosophy is a handmaid to her as mistress. For this reason sometimes divine wisdom argues from the principles of human philosophy: since also among philosophers the First Philosophy makes use of the teachings of all sciences in order to establish its purpose. Hence again both teachings do not follow the same order. For in the teaching of philosophy which considers creatures in themselves and leads us from them to the knowledge of God, the first consideration is about creatures, and the last of God: whereas in the teaching of faith which considers creatures only in their relation to God, the consideration about God takes the first place, and that about creatures the last. And thus it is more perfect: as being more like God's knowledge, for He beholds other things by knowing Himself.

Wherefore, according to this order, after what has been said in the First Book about God in Himself, it remains for us to treat of the things which proceed from Him.