Selection from An Introduction to the Philosophy of Animate Nature | Henry Koren, CSSp

(St. Louis: Herder, 1955), 182-183.

The human intellect does not acquire perfect knowledge of its object by the first act performed after the reception of the intelligible species. With respect to the acquisition of knowledge there are three kinds of intellectual actions, which are called simple apprehension, judgment, and reasoning.

Simple Apprehension. By an act of simple apprehension the intellect grasps the essence of an object, but does not affirm or deny anything. In saying that the intellect grasps the "essence" of the object, we do not mean that a first apprehension is sufficient to make the intellect know the nature of the object in all its specific details. All that is implied is that the intellect has some idea of the object, although this idea may be very general and vague.
Judgment. Subsequently to its first apprehension the intellect has other apprehensions, and thus is in a position to compare the objects apprehended and to affirm or deny that the y form a composite. This is called the act of judgment, in which the intellect understands the subject and the predicate as one inasmuch as they are parts of one proposition.

Reasoning. The intellect is capable also of proceeding from the understanding of one truth to that of another so as to gain explicit knowledge of another truth implied in the first. This is called reasoning. The power of reasoning is not a special potency but merely a different function of the potential intellect. The object of both reasoning and understanding is one and the same; only the way of attaining the object is different. Reasoning is compared to understanding as motion towards an object is to rest in the object reached, for by reasoning the intellect arrives at the understanding of an object. Obviously, motion and rest do not refer to different potencies but to one and the same.