After a clarification of the concept of concept the project of analysing the concept of man is defended (I), and it is concluded that to be human involves being both of a certain anatomical structure and a member of a race most of whose members are capable of theoretical and practical reasoning (II). Since further the development of essential capacities is necessary for members of a species to flourish, the ability to exercise the essential human capacities for theoretical and practical (...) reasoning is necessary for a man to live well (III). Besides its bearing on ideals of human flourishing, this conclusion would have a crucial bearing on moral issues, were it granted that there is an internal relation between morality and human flourishing (IV). Finally the conclusions of III are sustained against further objections (V). Educational and other practical implications of these conclusions are remarked upon throughout. (shrink)