I remained a socialist for several years, even after my rejection of Marxism; and if there could be such a thing as socialism combined with individual liberty, I would be a socialist still. For nothing could be better than living a modest, simple, and free life in an egalitarian society.

If you can't say it simply and clearly, keep quiet, and keep working on it till you can.

It is wrong to ask who will rule. The ability to vote a bad government out of office is enough. That is democracy.

We have the right not to tolerate the intolerant. We should tolerate even them whenever we can do so without running a great risk; but the risk may become so great that we cannot allow ourselves the luxury.

[Great scientists] are men of bold ideas, but highly critical of their own ideas: they try to find whether their ideas are right by trying first to find whether they are not perhaps wrong. They work with bold conjectures and severe attempts at refuting their own conjectures.

I have come to the conclusion that Darwinism is not a testable scientific theory, but a metaphysical research programme.

The moral decisions of others should be treated with respect, as long as such decisions do not conflict with the principle of tolerance.