On The Soul   

(c), one who is already realizing his knowledge-he is a knower in

actuality and in the most proper sense is knowing, e.g. this A. Both

the former are potential knowers, who realize their respective

potentialities, the one (a) by change of quality, i.e. repeated

transitions from one state to its opposite under instruction, the

other (b) by the transition from the inactive possession of sense or

grammar to their active exercise. The two kinds of transition are

distinct.

Also the expression 'to be acted upon' has more than one meaning; it

may mean either (a) the extinction of one of two contraries by the

other, or (b) the maintenance of what is potential by the agency of

what is actual and already like what is acted upon, with such likeness

as is compatible with one's being actual and the other potential.

For what possesses knowledge becomes an actual knower by a

transition which is either not an alteration of it at all (being in

reality a development into its true self or actuality) or at least

an alteration in a quite different sense from the usual meaning.

Hence it is wrong to speak of a wise man as being 'altered' when

he uses his wisdom, just as it would be absurd to speak of a builder

as being altered when he is using his skill in building a house.

What in the case of knowing or understanding leads from potentiality

to actuality ought not to be called teaching but something else.

That which starting with the power to know learns or acquires

knowledge through the agency of one who actually knows and has the

power of teaching either (a) ought not to be said 'to be acted upon'

at all or (b) we must recognize two senses of alteration, viz. (i) the

substitution of one quality for another, the first being the

contrary of the second, or (ii) the development of an existent quality

from potentiality in the direction of fixity or nature.

In the case of what is to possess sense, the first transition is due

to the action of the male parent and takes place before birth so

that at birth the living thing is, in respect of sensation, at the