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.
A.J. AyerIt appears, then, that ethics, as a branch of knowledge, is nothing more than a department of psychologyand sociology.
A.J. AyerWe say that a sentence is factually significant to any given person, if, and only if, he knows how to verify the proposition which it purports to express.
A.J. AyerBertrand Russell would not have wished to be called a saint of any description; but he was a great and good man.
A.J. AyerThe 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.
A.J. Ayer