My own belief is that in most ages and in most places obscure psychological forces led men to adopt systems involving quite unnecessary cruelty, and that this is still the case among the most civilized races at the present day.

No one gossips about other people's secret virtues.

The twin conceptions of sin and vindictive punishment seem to be at the root of much that is most vigorous, both in religion and politics.

It seems to me a fundamental dishonesty, and a fundamental treachery to intellectual integrity to hold a belief because you think it's useful and not because you think it's true.

We must be skeptical even of our skepticism.

Is there any knowledge in the world which is so certain that no reasonable man could doubt it?

When it was first proposed to establish laboratories at Cambridge, Todhunter, the mathematician, objected that it was unnecessary for students to see experiments performed, since the results could be vouched for by their teachers, all of them of the highest character, and many of them clergymen of the Church of England.