No moral system can rest solely on authority.

The principles of logic and mathematics are true simply because we never allow them to be anything else. And the reason for this is that we cannot abandon them without contradicting ourselves, without sinning against the rules which govern the use of language, and so making our utterances self-stultifying. In other words, the truths of logic and mathematics are analytic propositions or tautologies.

It is time, therefore, to abandon the superstition that natural science cannot be regarded as logically respectable until philosophers have solved the problem of induction. The problem of induction is, roughly speaking, the problem of finding a way to prove that certain empirical generalizations which are derived from past experience will hold good also in the future.

Bertrand Russell would not have wished to be called a saint of any description; but he was a great and good man.

While moral rules may be propounded by authority the fact that these were so propounded would not validate them.

I take it, therefore, to be a fact, that one's existence ends with death. I think it possible to show how this fact can be emotionally acceptable.

The ground for taking ignorance to be restrictive of freedom is that it causes people to make choices which they would not have made if they had seen what the realization of their choices involved.