These things, then, which have now been explained, being sufficiently understood, we will proceed to say a little on the subject of assent and approbation, which the Greeks call συγκατάθεσις. Not that the subject itself is not an extensive one, but because the foundations have been already laid a little while ago. For when we were explaining what power there was in the senses, this point was at the same time established, that many things were comprehended and perceived by the senses, which is a thing which cannot take place without assent. Secondly, as this is the principal difference between an inanimate and an animated being, that the inanimate being does nothing, but the animated one does something (for it is impossible even to imagine what kind of animal that can be which does nothing)—either sense must be taken from it, or else assent (which is wholly in our own power) must be given. But mind is in some degree denied to those beings whom they will not allow either to feel or to assent. For as it is inevitable that one scale of a balance must be depressed when a weight is put in it, so the mind, too, must yield to what is evident; for just as it is impossible for any animal to forbear discerning what is manifestly suited to its nature (the Greeks call that οἰκεῖον), so it is equally impossible for it to withhold its assent to a manifest fact which is brought under its notice. Although, if those principles which we have been maintaining are true, there is no advantage whatever in discussing assent. For he who perceives anything, assents immediately. But these inferences also follow,—that memory can have no existence without assent, no more can notions of things or arts. And what is most important of all is, that, although some things may be in our power, yet they will not be in the power of that man who assents to nothing. Where, then, is virtue, if nothing depends on ourselves? But it is above all things absurd that vices should be in the power of the agents, and that no one should do wrong except by deliberate consent to do so, and yet that this should not be the case with virtue; all the consistency and firmness of which depends on the things to which it has assented, and which it has approved. And altogether it is necessary that something should be perceived before we act, and before we assent to what is perceived; wherefore, he who denies the existence of perception or assent, puts an end to all action in life.