A philosopher may try to prove the truth of something he believed before he was a philosopher, but even if he succeeds, his belief never regain the untroubled character, and the settled place in his mind, which it had at first.

If a lack of empirical foundations is a defect of the theory of logical probability, it is also a defect of deductive logic.

But the stupidity which is common to all such explanations is, of course, simply that of proceeding as though the merits of a theory - such things as truth, or probability, or explanatory power - could not possibly be among the reasons for its currency.

We set ourselves to achieve a society that would be maximally tolerant. But that resolve not only gives maximum scope to the activities of those who have set themselves to achieve the maximally intolerant society. It also... paralyses our powers of resistance to them.