There is only one prospect worse than being chained to an intolerable existence: The nightmare of a botched attempt to end it.

If conquerors be regarded as the engine-drivers of History, then the conquerors of thought are perhaps the pointsmen who, less conspicuous to the traveler's eye, determine the direction of the journey.

Chemically induced hallucinations, delusions and raptures may be frightening or wonderfully gratifying; in either case they are in the nature of confidence tricks played on one's own nervous system.

Two half truths do not make a truth.

The fact is: I no longer believe in my own infallibility. That is why I am lost.

We know that virtue does not matter to history, and that crimes remain unpunished; but that every error had its consequences and venges itself unto the seventh generation.

Newton's apple and Cezanne's apple are discoveries more closely related than they seem.