A. J. Ayer

“It seems that I have spent my entire time trying to make life more rational and that it was all wasted effort.”

“There never comes a point where a theory can be said to be true. The most that one can claim for any theory is that it has shared the successes of all its rivals and that it has passed at least one test which they have failed.”

“I see philosophy as a fairly abstract activity, as concerned mainly with the analysis of criticism and concepts, and of course most usefully of scientific concepts.”

“No moral system can rest solely on authority.”

“I am using the word "perceive". I am using it here in such a way that to say of an object that it is perceived does not entail saying that it exists in any sense at all. And this is a perfectly correct and familiar usage of the word. If there is thought to be a difficulty here, it is perhaps because there is also a correct and familiar usage of the word "perceive", in which to say of an object that it is perceived does carry the implication that it exists.”

“There is philosophy, which is about conceptual analysis — about the meaning of what we say — and there is all of this … all of life.”