Skip navigation.

A. J. Ayer, Alfred Jules Ayer

(1910 - )


    British Philosopher, Compiler of Quotes, Author

    "I exist" does not follow from "there is a thought now." The fact that a thought occurs at a given moment does not entail that any other thought has occurred at any other moment, still less that there has occurred a series of thoughts sufficient to constitute a single self. As Hume conclusively showed, no one event intrinsically points to any other. We infer the existence of events which we are not actually observing, with the help of general principle. But these principles must be obtained inductively. By mere deduction from what is immediately given we cannot advance a single step beyond. And, consequently, any attempt to base a deductive system on propositions which describe what is immediately given is bound to be a failure.
    A point which is not sufficiently brought out by Russell, if indeed it is recognized by him at all, is that every logical proposition is valid in its own right. Its validity does not depend upon its being incorporated in a system, and deduced from certain propositions which are taken as self-evident. The construction of systems of logic is useful as a means of discovering and certifying analytic propositions, but it is not in principle essential even for this purpose. For it is possible to conceive of a symbolism in which every analytic proposition could be seen to be analytic in virtue of its form alone. The fact that the validity of an analytic proposition in no way depends on its being deducible from other analytic propositions is our justification for disregarding the question whether the propositions of mathematics are reducible to propositions of formal logic, in the way that Russell supposed. For even if it is the case that the definition of a cardinal number as a class of classes similar to a given class is circular, and it is not possible to reduce mathematical notions to purely logical notions, it will still remain true that the propositions of mathematics are analytic propositions. They will form a special class of analytic propositions, containing special terms, but they will be none the less analytic for that. For the criterion of an analytic proposition is that its validity should follow simply from the definition of the terms contained in it, and this condition is fulfilled by the propositions of pure mathematics.
    For we shall maintain that no statement which refers to a ?reality? transcending the limits of all possible sense-experience can possibly have any literal significance; from which it follows that the labors of those who have striven to describe such a reality have all been devoted to the production of nonsense.
    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.
    I saw a Divine Being. I?m afraid I?m going to have to revise all my various books and opinions.
    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.
    I suddenly stopped and looked out at the sea and thought, my God, how beautiful this is ... for 26 years I had never really looked at it before.
    If now I? say "Stealing money is wrong," I produce a sentence which has no factual meaning ? that is, expresses no proposition which can be either true or false. It is as if I had written "Stealing money!!" ? where the shape and thickness of the exclamation marks show, by a suitable convention, that a special sort of moral disapproval is the feeling which is being expressed.
    If the existence of such a god were probable, then the proposition that he existed would be an empirical hypothesis. And in that case it would be possible to deduce from it, and other empirical hypotheses, certain experiential propositions which were not deducible from those other hypotheses alone. But in fact this is not possible. It is sometimes claimed, indeed, that the existence of a certain sort of regularity in nature constitutes sufficient evidence for the existence of a god. But if the sentence "God exists" entails to more than that certain types of phenomena occur in certain sequences, then to assert the existence of a god will be simply equivalent to asserting that there is the requisite regularity in nature; and no religious man would admit that this was all he intended to assert in asserting the existence of a god. He would say that in talking about God, he was talking about a transcendent being who might be known through certain empirical manifestations, but certainly could not be defined in terms of those manifestations. But in that case the term "god" is a metaphysical term. And 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.
    In other words, the propositions of philosophy are not factual, but linguistic in character - that is, they do not describe the behavior 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.
    First Name: 
    A. J.
    Last Name: 
    Ayer, Alfred Jules Ayer
    Birth Date: 
    Death Date: 
    British Philosopher, Compiler of Quotes, Author