Knowledge, therefore, acquired in the present life does not remain in the separated soul, as regards what belongs to the sensitive powers; but as regards what belongs to the intellect itself, it must remain; because, as the Philosopher says (De Long. et Brev. Vitae ii), a form may be corrupted in two ways; first, directly, when corrupted by its contrary, as heat, by cold; and secondly, indirectly, when its subject is corrupted. Now it is evident that human knowledge is not corrupted through corruption of the subject, for the intellect is an incorruptible faculty, as above stated (Q. 79, A. 2, ad 2). Neither can the intelligible species in the passive intellect be corrupted by their contrary; for there is no contrary to intelligible "intentions," above all as regards simple intelligence of "what a thing is." But contrariety may exist in the intellect as regards mental composition and division, or also reasoning; so far as what is false in statement or argument is contrary to truth. And thus knowledge may be corrupted by its contrary when a false argument seduces anyone from the knowledge of truth. For this reason the Philosopher in the above work mentions two ways in which knowledge is corrupted directly: namely, "forgetfulness" on the part of the memorative power, and "deception" on the part of a false argument. But these have no place in the separated soul. Therefore we must conclude that the habit of knowledge, so far as it is in the intellect, remains in the separated soul.
Reply Obj. 1: The Apostle is not speaking of knowledge as a habit, but as to the act of knowing; and hence he says, in proof of the assertion quoted, "Now, I know in part."
Reply Obj. 2: As a less good man may exceed a better man in bodily stature, so the same kind of man may have a habit of knowledge in the future life which a better man may not have. Such knowledge, however, cannot be compared with the other prerogatives enjoyed by the better man.
Reply Obj. 3: These two kinds of knowledge are not of the same species, so there is no impossibility.
Reply Obj. 4: This objection considers the corruption of knowledge on the part of the sensitive powers. _______________________
SIXTH ARTICLE [I, Q. 89, Art. 6]
Whether the Act of Knowledge Acquired Here Remains in the Separated
Soul?
Objection 1: It would seem that the act of knowledge here acquired does not remain in the separated soul. For the Philosopher says (De Anima i, 4), that when the body is corrupted, "the soul neither remembers nor loves." But to consider what is previously known is an act of memory. Therefore the separated soul cannot retain an act of knowledge here acquired.
Obj. 2: Further, intelligible species cannot have greater power in the separated soul than they have in the soul united to the body. But in this life we cannot understand by intelligible species without turning to phantasms, as shown above (Q. 84, A. 7). Therefore the separated soul cannot do so, and thus it cannot understand at all by intelligible species acquired in this life.
Obj. 3: Further, the Philosopher says (Ethic. ii, 1), that "habits produce acts similar to those whereby they are acquired." But the habit of knowledge is acquired here by acts of the intellect turning to phantasms: therefore it cannot produce any other acts. These acts, however, are not adapted to the separated soul. Therefore the soul in the state of separation cannot produce any act of knowledge acquired in this life.