Whether Another Doctrine is Necessary, besides the Philosophical Sciences
We proceed to the first article thus:
1. It seems that there is no need for any other doctrine besides the philosophical sciences. Man should not strive to know what is above reason, since it is said in Ecclesiasticus 3:22: |seek not to know what is higher than thyself.| Now what is within the reach of reason is adequately dealt with in the philosophical sciences. It seems superfluous, therefore, that there should be another doctrine besides the philosophical sciences.
2. Again, a doctrine can be concerned only with |what is,| since only what is true can be known, and whatever is true, is. Now all things which |are| are dealt with in the philosophical sciences, which treat even of God, wherefore one part of philosophy is called theology, or the science of divine things, as the philosopher says in 6 Metaph. (Commentary II). There was therefore no need for another doctrine, besides the philosophical sciences.
On the other hand: it is said in II Tim.3:16: |All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness. . . .| Now the divinely inspired Scriptures are quite distinct from the philosophical sciences, which are devised by human reason. It is therefore expedient that there should be another science which is divinely inspired, besides the philosophical sciences.
I answer: it was necessary for man's salvation that there should be a doctrine founded on revelation, as well as the philosophical sciences discovered by human reason. It was necessary, in the first place, because man is ordained to God as his end, who surpasses the comprehension of reason, according to Isa.64:4: |neither hath the eye seen, O God, besides thee, what he hath prepared for him that waiteth for him.| Men must have some foreknowledge of the end to which they ought to direct their intentions and actions. It was therefore necessary that some things which transcend human reason should be made known through divine revelation. It was necessary also that man should be instructed by divine revelation even in such things concerning God as human reason could discover. For such truth about God as could be discovered by reason would be known only by the few, and that after a long time, and mixed with many errors. Now the whole salvation of man, which lies in God, depends on the knowledge of this truth. It was therefore necessary that men should be instructed in divine things through divine revelation, in order that their salvation might come to pass the more fittingly and certainly. It was necessary, therefore, that there should be a sacred doctrine given through revelation, as well as the philosophical sciences discovered by reason.
On the first point: although things which are beyond human knowledge are not to be sought by man through reason, such things are revealed by God, and are to be accepted by faith. Hence Ecclesiasticus adds in the same passage: |many things beyond human understanding have been revealed unto thee| (3:25).
On the second point: sciences are distinguished by their different ways of knowing. The astronomer and the naturalist prove the same thing, for example, that the world is round. But the astronomer proves it by mathematics, without reference to matter, whereas the naturalist proves it by examining the physical. There is no reason, then, why the same things, which the philosophical sciences teach as they can be known by the light of natural reason, should not also be taught by another science as they are known through divine revelation. The theology which depends on sacred Scripture is thus generically different from the theology which is a part of philosophy.