Aristotle, Nicomachean Ethics
H. Rackham, Ed.

[9] But if life itself is good and pleasant （as it appears to be, because all men desire it, and virtuous and supremely happy men most of all, since their way of life is most desirable and their existence the most blissful） ; and if one who sees is conscious¹ that he sees, one who hears that he hears, one who walks that he walks, and similarly for all the other human activities there is a faculty that is conscious of their exercise, so that whenever we perceive, we are conscious that we perceive, and whenever we think, we are conscious that we think, and to be conscious that we are perceiving or thinking is to be conscious that we exist （for existence, as we saw, is sense-perception or thought）; and if to be conscious one is alive is a pleasant thing in itself （for life is a thing essentially good, and to be conscious that one possesses a good thing is pleasant） ; and if life is desirable, and especially so for good men, because existence is good for them, and so pleasant （because they are pleased by the perception of what is intrinsically good） ;