Theories of love are found in the works of scientists, philosophers, and theologians.

The best protection against propaganda of any sort is the recognition of it for what it is. Only hidden and undetected oratory is really insidious. What reaches the heart without going through the mind is likely to bounce back and put the mind out of business. Propaganda taken in that way is like a drug you do not know you are swallowing. The effect is mysterious; you do not know afterwards why you feel or think the way you do.

More consequences for thought and action follow the affirmation or denial of God than from answering any other basic question.

Men value things in three ways: as useful, as pleasant or sources of pleasure, and as excellent, or as intrinsically admirable or honorable.

There is a strange fact about the human mind, a fact that differentiates the mind sharply from the body. The body is limited in ways that the mind is not. One sign of this is that the body does not continue indefinitely to grow in strength and develop in skill and grace. By the time most people are thirty years old, their bodies are as good as they will ever be; in fact, many persons' bodies have begun to deteriorate by that time. But there is no limit to the amount of growth and development that the mind can sustain. The mind does not stop growing at any particular age.

There are genuine mysteries in the world that mark the limits of human knowing and thinking. Wisdom is fortified, not destroyed, by understanding its limitations. Ignorance does not make a fool as surely as self-deception.

To agree without understanding is inane. To disagree without understanding is impudent.