“There are plenty of people, in need of our attention, who have very little with which to repay us. But I feel that we are well within our rights if we cultivate the acquaintance of persons whom we have discovered to be in possession of specialized talents in the field of character-building. One such acquaintance may serve as a stimulant to us; another a sedative. One man laughs his fears and frets away and another growls at them. It is fortunate for us if we can recognize the exact effect that other people have on us. Then we know when to seek or avoid them.”