...For there is no doubt a truth in the view that [people] taken by and large, and neglecting individual differences, are capable of a kind of rational self-control which no other animal attains. Couple this with the persistent recognitions of individual differences which is found throughout Aristotle as an inheritor of the Greek medical tradition, and it seems persuasive that the way of life for man as man would center around the control of the self by reason. Actually hidden premises are involved and hidden preferences. For it would by no means follow that it is best for each individual, or even for [humankind], to give over the control of life to that which differentiates [people] from other animals; it would not necessarily be to the advantage of animals with a physical organ which no other animal possessed to favor the unrestrained growth of that organ or its dominance over all other organs.

Charles W. Morris, Paths of Life