"For the present let us be content to have established that of the two uses of
`potentiality', the one according to which a boy might be called potentially a
general, and the other according to which a man of full age might be so called,
it is the latter which applies to that which can perceive.  But as this
distinction has no word to mark it, although the fact and the nature of the
distinction have been established, we are compelled to use the terms to suffer
or be acted upon and to be qualitatively changed as if they were the proper
terms.  Now, as has been explained, that which can perceive is potentially such
as the perceptible object is in actuality.  While it is being acted upon, it is
not yet similar, but, when once it has been acted upon, it is similar and has
the same character as the sensible object."<p>
<p>
	(From <i>De Anima</i>, II, 5, 417b 28 ff)<p>