Objection 1: It would seem that the first man did not know all things. For if he had such knowledge it would be either by acquired species, or by connatural species, or by infused species. Not, however, by acquired species; for this kind of knowledge is acquired by experience, as stated in Metaph. i, 1; and the first man had not then gained experience of all things. Nor through connatural species, because he was of the same nature as we are; and our soul, as Aristotle says (De Anima iii, 4), is "like a clean tablet on which nothing is written." And if his knowledge came by infused species, it would have been of a different kind from ours, which we acquire from things themselves.
Obj. 2: Further, individuals of the same species have the same way of arriving at perfection. Now other men have not, from the beginning, knowledge of all things, but they acquire it in the course of time according to their capacity. Therefore neither did Adam know all things when he was first created.
Obj. 3: Further, the present state of life is given to man in order that his soul may advance in knowledge and merit; indeed, the soul seems to be united to the body for that purpose. Now man would have advanced in merit in that state of life; therefore also in knowledge. Therefore he was not endowed with knowledge of all things.
On the contrary, Man named the animals (Gen. 2:20). But names should be adapted to the nature of things. Therefore Adam knew the animals' natures; and in like manner he was possessed of the knowledge of all other things.
I answer that, In the natural order, perfection comes before imperfection, as act precedes potentiality; for whatever is in potentiality is made actual only by something actual. And since God created things not only for their own existence, but also that they might be the principles of other things; so creatures were produced in their perfect state to be the principles as regards others. Now man can be the principle of another man, not only by generation of the body, but also by instruction and government. Hence, as the first man was produced in his perfect state, as regards his body, for the work of generation, so also was his soul established in a perfect state to instruct and govern others.
Now no one can instruct others unless he has knowledge, and so the first man was established by God in such a manner as to have knowledge of all those things for which man has a natural aptitude. And such are whatever are virtually contained in the first self-evident principles, that is, whatever truths man is naturally able to know. Moreover, in order to direct his own life and that of others, man needs to know not only those things which can be naturally known, but also things surpassing natural knowledge; because the life of man is directed to a supernatural end: just as it is necessary for us to know the truths of faith in order to direct our own lives. Wherefore the first man was endowed with such a knowledge of these supernatural truths as was necessary for the direction of human life in that state. But those things which cannot be known by merely human effort, and which are not necessary for the direction of human life, were not known by the first man; such as the thoughts of men, future contingent events, and some individual facts, as for instance the number of pebbles in a stream; and the like.
Reply Obj. 1: The first man had knowledge of all things by divinely infused species. Yet his knowledge was not different from ours; as the eyes which Christ gave to the man born blind were not different from those given by nature.
Reply Obj. 2: To Adam, as being the first man, was due a degree of perfection which was not due to other men, as is clear from what is above explained.
Reply Obj. 3: Adam would have advanced in natural knowledge, not in the number of things known, but in the manner of knowing; because what he knew speculatively he would subsequently have known by experience. But as regards supernatural knowledge, he would also have advanced as regards the number of things known, by further revelation; as the angels advance by further enlightenment. Moreover there is no comparison between advance in knowledge and advance in merit; since one man cannot be a principle of merit to another, although he can be to another a principle of knowledge.