Immortality is the condition of a dead man who doesn't believe he is dead

Men become civilized, not in proportion to their willingness to believe, but in their readiness to doubt.

The ideal way to get rid of any infectious disease would be to shoot instantly every person who comes down with it.

Those who can't teach - administrate. Those who can't administrate - go into politics.

The prophesying business is like writing fugues; it is fatal to every one save the man of absolute genius.

Experience is a poor guide to man, and is seldom followed. What really teaches a man is not experience, but observation.

[Science] must be amoral by its very nature: The minute it begins separating facts into the two categories of good ones and bad ones it ceases to be science and becomes a mere nuisance, like theology.