The books on manager development for instance envisage truly a `man for all seasons’ in their picture of `the manager of tomorrow’. A senior executive, we are told, should have extraordinary abilities as an analyst and as a decisionmaker. He should be good at working with people and at understanding organization and power relations, good at mathematics and have artistic insight and creative imagination. What seems to be wanted is universal genius; and universal genius has always been in scarce supply. The experience of the human race indicates strongly that the only person in abundant supply is the universal incompetent. We will therefore have to staff our organizations with people who at best excel in one of these abilities. And then they are more than likely to lack any but the most modest endowment in the others.

-Peter F. Drucker, The Effective Executive