Before impugning an opponent's motives, even when they legitimately may be impugned, answer his arguments.

If one shoots at a king, one must not miss.

Idealism, alas, does not protect one from ignorance, dogmatism, and foolishness.

Everyone who remembers his own education remembers teachers, not methods and techniques. The teacher is the heart of the educational system.

No one who accepts the sovereignty of truth can be a foot soldier in a party or movement. He will always find himself out of step.

Everyone recognizes a distinction between knowledge and wisdom. . . Wisdom is a kind of knowledge. It is knowledge of the nature, career, and consequences of human values. Since these cannot be separated from the human organism and the social scene, the moral ways of man cannot be understood without knowledge of the ways of things and institutions.

Stupidity is sometimes the greatest of historical forces.