Scientific method, although in its more refined forms it may seem complicated, is in essence remarkably simply. It consists in observing such facts as will enable the observer to discover general laws governing facts of the kind in question. The two stages, first of observation, and second of inference to a law, are both essential, and each is susceptible of almost indefinite refinement. (1931)

All forms of fear produce fatigue.

When we have told how things behave when they are electrified, and under what circumstances they are electrified, we have told all there is to know

There can't be a practical reason for believing something that is not true.

I say quite deliberately that the Christian religion, as organized in its Churches, has been and still is the principal enemy of moral progress in the world.

The man who is unhappy will, as a rule, adopt an unhappy creed, while the man who is happy will adopt a happy creed; each may attribute his happiness or unhappiness to his beliefs, while the real causation is the other way round.

One of the chief obstacles to intelligence is credulity, and credulity could be enormously diminished by instructions as to the prevalent forms of mendacity. Credulity is a greater evil in the present day than it ever was before, because, owing to the growth of education, it is much easier than it used to be to spread misinformation, and, owing to democracy, the spread of misinformation is more important than in former times to the holders of power.