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
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