ALFRED JULES AYER

No morality can be founded on authority, even if the authority were divine.

We 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.

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.

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.

But if science may be said to be blind without philosophy, it is true also that philosophy is virtually empty without science.

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.

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.

If 'god' is a metaphysical term, then it cannot be even probable that a god exists. For to say that 'God exists' is to make a metaphysical utterance which cannot be either true or false. And by the same criterion, no sentence which purports to describe the nature of a transcendent god can possess any literal significance.

If one takes full account of the persecution of heretics, the frequency and savagery of the religious wars which Christianity had endangered, the harm caused, especially to children, by the pernicious doctrine of original sin, a case could be made for saying that the world would have been better off without Christianity.

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

In other words, the propositions of philosophy are not factual, but linguistic in character - that is, they do not describe the behaviour of physical, or even mental, objects; they express definitions, or the formal consequences of definitions. Accordingly we may say that philosophy is a department of logic. For we will see that the characteristic mark of a purely logical enquiry, is that it is concerned with the formal consequences of our definitions and not with questions of empirical fact.

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

A prevalent fallacy is the assumption that a proof of an afterlife would also be a proof of the existence of a deity. This is far from being the case. If, as I hold, there is no good reason to believe that a god either created or presides over this world, there is equally no good reason to believe that a god created or presides over the next world, on the unlikely supposition that such a thing exists.

It appears, then, that ethics, as a branch of knowledge, is nothing more than a department of psychologyand sociology.

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.

The traditional disputes of philosophers are, for the most part, as unwarranted as they are unfruitful. The surest way to end them is to establish beyond question what should be the purpose and method of a philosophical enquiry. And this is by no means so difficult a task as the history of philosophy would lead one to suppose. For if there are any questions which science leaves it to philosophy to answer, a straightforward process of elimination must lead to their discovery.

It is possible to be a meta-physician without believing in a transcendent reality; for we shall see that many metaphysical utterances are due to the commission of logical errors, rather than to a conscious desire on the part of their authors to go beyond the limits of experience.

I saw a Divine Being. I'm afraid I'm going to have to revise all my various books and opinions.

If the assertion that there is a god is nonsensical, then the atheist's assertion that there is no god is equally nonsensical, since it is only a significant proposition that can be significantly contradicted.

The fact that people have religious experiences is interesting from the psychological point of view, but it does not in any way imply that there is such a thing as religious knowledge...Unless he can formulate this 'knowledge' in propositions that are empirically verifiable, we may be sure that he is deceiving himself.

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

The traditional disputes of philosophers are, for the most part, as unwarranted as they are unfruitful.

Why should you mind being wrong if someone can show you that you are?

The misfortunes which God is represented in the book of Job as allowing Satan to inflict on Job, merely to test his faith, are indications, if not of positive malevolence, at least of a suspicious and ruthless insecurity, which is characteristic more of a tyrant than of a wholly powerful and benevolent deity.

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