Think before thou speakest.

Fear of serious injury cannot alone justify suppression of free speech and assembly. Men feared witches and burned women. It is the function of speech to free men from the bondage of irrational fears.

Some people’s idea of free speech is that they are free to say what they like, but if anyone says anything back, that is an outrage.

Understanding a question is half an answer.

We shall soon be in a world in which a man may be howled down for saying that two and two make four, in which people will persecute the heresy of calling a triangle a three-sided figure, and hang a man for maddening a mob with the news that grass is green.

Everything you say should be true but not everything true should be said.

Man's tongue is soft, and bone doth lack; yet a stroke therewith may break a man's back.

If you want to be happy, set a goal that commands your thoughts, liberates your energy and inspires your hopes.

An hour of planning can say you 10 hours of doing.

Think not disdainfully of death, but look on it with favor; for even dearth is one of the things that Nature wills.

I know only that what is moral is what you feel good after and what is immoral is what you feel bad after.

I frame no hypotheses; for whatever is not deduced from the phenomena is to be called an hypothesis; and hypotheses, whether metaphysical or physical, whether of occult qualities or mechanical, have no place in experimental philosophy.

The oldest, shortest words - “yes” and “no” - are those which require the most thought.

The world is a comedy to those that think, and a tragedy to those that feel.

It is hard to fight desire; but to control it is the sign of a reasonable man.