The theory of free speech, that truth is so much larger and stranger and more many-sided than we know of, that it is very much better at all costs to hear everyone's account of it, is a theory which has been justified on the whole by experiment, but which remains a very daring and even a very surprising theory. It is really one of the great discoveries of the modern time.

It is largely because the free-thinkers, as a school, have hardly made up their minds whether they want to be more optimist or more pessimist than Christianity that their small but sincere movement has failed.

To do Mohammed justice, his main attack was against the idolatries of Asia. Only he thought, just as the Arians did and just as the Unitarians do, that he could attack them better with a greater approximation to plain theism. What distinguishes his heresy from anything like an Arian or Albigensian heresy is that, as it sprang up on the borders of Christendom, it could spread outwards to a barbaric world.

It is not funny that anything else should fall down; only that a man should fall down... Why do we laugh? Because it is a grave religious matter: it is the Fall of Man. Only man can be absurd: for only man can be dignified.

Whenever you remove any fence, always pause long enough to ask why it was put there in the first place.

Facts by themselves can often feed the flame of madness, because sanity is a spirit.

Even in a minute instance, it is best to look first to the main tendencies of Nature. A particular flower may not be dead in early winter, but the flowers are dying; a particular pebble may never be wetted with the tide, but the tide is coming in. To the scientific eye all human history is a series of collective movements, destructions or migrations, like the massacre of flies in winter or the return of birds in spring.