Simple solutions seldom are. It takes a very unusual mind to undertake analysis of the obvious.

It takes an extraordinary intelligence to contemplate the obvious.

The aim of science is to seek the simplest explanations of complex facts. We are apt to fall into the error of thinking that the facts are simple because simplicity is the goal of our quest. The guiding motto in the life of every natural philosopher should be, 'Seek simplicity and distrust it.

In formal logic, a contradiction is the signal of defeat, but in the evolution of real knowledge it marks the first step in progress toward a victory

Civilizations can only be understood by those who are civilized.

If a dog jumps into your lap, it is because he is fond of you; but if a cat does the same thing, it is because your lap is warmer.