The Republic by Plato Part 1 Page 92

I might say the same of the ears; when deprived of their own proper excellence they cannot fulfil their end?

True.

And the same observation will apply to all other things?

I agree.

Well; and has not the soul an end which nothing else can fulfil? for example, to superintend and command and deliberate and the like. Are not these functions proper to the soul, and can they rightly be assigned to any other?

To no other.

And is not life to be reckoned among the ends of the soul?

Assuredly, he said.

And has not the soul an excellence also?

Yes.