On the Soul (De Anima) with Simplicius Commentary

the powers of the soul and the division that Aristotle gives of the rational part of it.

Regarding the other treatises, I shall only add that they are consummate in their kind, that they follow one another in a scientific order, and that they are filled with the most interesting information. In this last particular, indeed, a genuine modern will doubtless be surprised to find the Stagirite asserting, in his treatise On Sense and Sensibles (p. 141), “that it is possible colors may exist in the same manner as symphonies, and that all colors have a ratio to each other.” And he will be even more surprised to find that the third Newtonian law, as it is called—that action and reaction are equal—was known to this mighty genius, and known by him more accurately than by Newton. For Newton asserts that action and reaction are always equal, but Aristotle shows, in his treatise On the Generation of Animals (p. 390), that this equality does not hold in some instances. The former, however, only ranks among the greatest of modern mathematicians, but the latter ranks among the greatest of ancient philosophers. And,

In order, therefore, to understand the following treatise On the Soul, it is necessary to speak, in the first place, of the powers of the soul and show in how many ways they are divided, and what name each of them is allotted. In the next place, it is required to enumerate the opinions of the ancients respecting these powers; and in the third place, to unfold, through division, the true opinion concerning them. In the first place, then, the psychical powers (or powers belonging to the soul),