Language, Truth, and Logic
Encyclopedia
Language, Truth, and Logic is a work of philosophy
by Alfred Jules Ayer, published in 1936 when Ayer was 26 (though it was in fact completed by age 25). It was crucial in bringing some of the ideas of the Vienna Circle
and the logical empiricists
to the attention of the English-speaking world.
This book defines, explains, and argues for the verification principle of logical positivism
, sometimes referred to as the "criterion of significance" or "criterion of meaning". It explains how the principle of verifiability may be applied to the problems of philosophy.
The text has eight chapters:
's Logik, Sprache, Philosophie auffassung.
) or capable of being verified.
According to Ayer, analytic statements are tautologies. A tautology is a statement that is necessarily true, true by definition, and true under any conditions. A tautology is a repetition of the meaning of a statement, using different words or symbols. According to Ayer, the statements of logic and mathematics are tautologies. Tautologies are true by definition, and thus their validity does not depend on empirical
testing.
Synthetic statements, or empirical propositions, assert or deny something about the real world. The validity of synthetic statements is not established merely by the definition of the words or symbols they contain. According to Ayer, if a statement expresses an empirical proposition, then the validity of the proposition is established by its empirical verifiability.
Propositions are statements that have conditions under which they can be verified. By the verification principle, meaningful statements have conditions under which their validity can be affirmed or denied.
Statements that are not meaningful cannot be expressed as propositions. Every verifiable proposition is meaningful, although it may be either true or false. Every proposition asserts or denies something, and thus is either true or false.
Ayer also distinguishes between practical and theoretical verifiability. Propositions for which we do not have a practical means of verification may still be meaningful if we can verify them in principle.
Literal meaning must also be distinguished from factual meaning. Literal meaning is an attribute of statements that are either analytic or empirically verifiable. Factual meaning is an attribute of statements that are meaningful without being analytic. Thus, statements that have factual meaning say something about the real world.
Ayer agrees with Hume that there are two main classes of propositions: those that concern 'relations of ideas,' and those that concern 'matters of fact.' Propositions about 'relations of ideas' include the a priori propositions of logic and mathematics. Propositions about 'matters of fact,' on the other hand, make assertions about the empirical world.
Ayer argues that philosophic propositions are analytic, and that they are concerned with 'relations of ideas.' The task of philosophy is to clarify the logical relationships of empirical propositions. If the meaning of propositions is defined by verifiability, then philosophy cannot provide speculative truths about metaphysical statements that cannot be empirically verified.
A significant consequence of abandoning metaphysics as a concern of philosophy is a rejection of the view that the function of philosophy is to propose basic principles of meaning and to construct a deductive system
by offering the consequences of these principles of meaning as a complete picture of reality. But this is, in fact, what Ayer does, in presenting the principle of verifiability as a criterion of meaningfulness for any empirical proposition.
According to Ayer, no proposition concerning 'matters of fact' can ever be shown to be necessarily true, because there is always a possibility that it may be refuted by further empirical testing. Logical certainty is possible only for analytic observations, which are tautologies, and not for empirical observations concerning 'matters of fact.'
Ayer explains that his radical empiricism is opposed to rationalism. Rationalism asserts that there are truths about the world that can be known by a priori reasoning, or independently of experience. According to the principle of verifiability, propositions about 'matters of fact' can be meaningful only if they are capable of being empirically verified.
Ayer agrees with, and elaborates on, Kant’s explanation of the distinction between analytic and synthetic judgments. According to Ayer, a proposition is analytic if its validity depends only on the definitions of the symbols it contains. A proposition is synthetic if its validity is determined by the facts of experience.
Analytic observations give us new knowledge, because they reveal unsuspected implications of our statements and beliefs. But analytic observations do not give us new knowledge of matters of fact, because they only tell us what is already known.
In the same manner, assertions of value have meaning only insofar as they are verifiable. If an ethical or aesthetic judgment cannot be subjected to empirical testing, then it is meaningless. An empirical test may be practical or theoretical.
According to Ayer, when we argue about whether a value-judgment is right or wrong, we are really arguing about the empirical facts on which a value-judgment is based, or about the logical interpretation of empirical facts. We cannot argue about something that cannot be expressed as a proposition. We can only argue about something that can be analytically or empirically verified.
For Ayer, metaphysical statements, such as statements about transcendent reality, have no objective validity, and therefore are meaningless. Examples of this lack of meaning include statements about the existence or nonexistence of God. According to Ayer, such statements can be neither proven nor disproven, and cannot be validated or invalidated by empirical testing.
to test a machine's capability to demonstrate intelligence (consciousness).
The principle of verifiability, however, may become a means to arbitrarily reject any abstract or transcendent concept, such as “truth,” “justice,” or "virtue." Such concepts are seen as having no literal meaning. Thus, Ayer’s viewpoint may become a radical scepticism. Ethics, aesthetics
, and religion are all viewed as meaningless, as having no literal meaning. Ethical concepts are seen merely as expressions of feeling. Ethical or aesthetic concepts are seen as having no factual content, and therefore cannot be accepted as valid or invalid.
Ayer is careful to explain that the verification principle is a definition of meaning, and that it is not an empirical proposition. He admits that there are other possible definitions of meaning.
The most frequently-expressed reservation about the principle is whether it is itself verifiable; this was addressed in the fictional dialogue "Logical Positivism: a discussion". Ayer believed that it could be derived analytically from usual definitions of words like "understanding". He admitted that one could then ask for verification of that definition and then carry on into an infinite regress. Ayer considered the latter option to be simply not worth consideration, although philosophers like Donald Davidson
and Richard Rorty
have since used it to undermine the concrete view of language found in works like Language, Truth and Logic.
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
by Alfred Jules Ayer, published in 1936 when Ayer was 26 (though it was in fact completed by age 25). It was crucial in bringing some of the ideas of the Vienna Circle
Vienna Circle
The Vienna Circle was an association of philosophers gathered around the University of Vienna in 1922, chaired by Moritz Schlick, also known as the Ernst Mach Society in honour of Ernst Mach...
and the logical empiricists
Logical positivism
Logical positivism is a philosophy that combines empiricism—the idea that observational evidence is indispensable for knowledge—with a version of rationalism incorporating mathematical and logico-linguistic constructs and deductions of epistemology.It may be considered as a type of analytic...
to the attention of the English-speaking world.
This book defines, explains, and argues for the verification principle of logical positivism
Logical positivism
Logical positivism is a philosophy that combines empiricism—the idea that observational evidence is indispensable for knowledge—with a version of rationalism incorporating mathematical and logico-linguistic constructs and deductions of epistemology.It may be considered as a type of analytic...
, sometimes referred to as the "criterion of significance" or "criterion of meaning". It explains how the principle of verifiability may be applied to the problems of philosophy.
The text has eight chapters:
- I. The Elimination of Metaphysics
- II. The Function of Philosophy
- III. The Nature of Philosophical Analysis
- IV. The A Priori
- V. Truth and Probability
- VI. Critique of Ethics and Theology
- VII. The Self and the Common World
- VIII. Solutions of Outstanding Philosophical Disputes
Historical background
According to Ayer's autobiographical book, Part of My Life, it was work he started in the summer and autumn of 1933 that eventually led to Language, Truth and Logic, specifically "Demonstration of the Impossibility of Metaphysics", which was later published in Mind under the editorship of G.E. Moore. The title of the book was taken ("To some extent plagiarized" according to Ayer) from Friedrich WaismannFriedrich Waismann
Friedrich Waismann was an Austrian mathematician, physicist, and philosopher. He is best known for being a member of the Vienna Circle and one of the key theorists in logical positivism.-Birth & Early Interest in Philosophy:...
's Logik, Sprache, Philosophie auffassung.
Criterion of meaning
Ayer explains that the principle of verifiability may be used as a criterion to determine whether a statement is meaningful. To be meaningful, a statement must be either analytic (i.e. a tautologyTautology (logic)
In logic, a tautology is a formula which is true in every possible interpretation. Philosopher Ludwig Wittgenstein first applied the term to redundancies of propositional logic in 1921; it had been used earlier to refer to rhetorical tautologies, and continues to be used in that alternate sense...
) or capable of being verified.
According to Ayer, analytic statements are tautologies. A tautology is a statement that is necessarily true, true by definition, and true under any conditions. A tautology is a repetition of the meaning of a statement, using different words or symbols. According to Ayer, the statements of logic and mathematics are tautologies. Tautologies are true by definition, and thus their validity does not depend on empirical
Empirical
The word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....
testing.
Synthetic statements, or empirical propositions, assert or deny something about the real world. The validity of synthetic statements is not established merely by the definition of the words or symbols they contain. According to Ayer, if a statement expresses an empirical proposition, then the validity of the proposition is established by its empirical verifiability.
Propositions are statements that have conditions under which they can be verified. By the verification principle, meaningful statements have conditions under which their validity can be affirmed or denied.
Statements that are not meaningful cannot be expressed as propositions. Every verifiable proposition is meaningful, although it may be either true or false. Every proposition asserts or denies something, and thus is either true or false.
Types of verification
Ayer distinguishes between ‘strong’ and ‘weak’ verification, noting that there is a limit to how conclusively a proposition can be verified. ‘Strong’ (conclusive) verification is not possible for any empirical proposition, because the validity of any proposition always depends upon further experience. ‘Weak’ (probable) verification, on the other hand, is possible for any empirical proposition.Ayer also distinguishes between practical and theoretical verifiability. Propositions for which we do not have a practical means of verification may still be meaningful if we can verify them in principle.
Literal meaning must also be distinguished from factual meaning. Literal meaning is an attribute of statements that are either analytic or empirically verifiable. Factual meaning is an attribute of statements that are meaningful without being analytic. Thus, statements that have factual meaning say something about the real world.
Ayer agrees with Hume that there are two main classes of propositions: those that concern 'relations of ideas,' and those that concern 'matters of fact.' Propositions about 'relations of ideas' include the a priori propositions of logic and mathematics. Propositions about 'matters of fact,' on the other hand, make assertions about the empirical world.
Ayer argues that philosophic propositions are analytic, and that they are concerned with 'relations of ideas.' The task of philosophy is to clarify the logical relationships of empirical propositions. If the meaning of propositions is defined by verifiability, then philosophy cannot provide speculative truths about metaphysical statements that cannot be empirically verified.
Metaphysics attacked
Ayer rejects the metaphysical thesis that philosophy can give us knowledge of a transcendent reality. He dismisses metaphysical arguments, calling them nonsense, and saying that they cannot be empirically verified. He argues that metaphysical statements have no literal meaning, and that they cannot be subjected to criteria of truth or falsehood.A significant consequence of abandoning metaphysics as a concern of philosophy is a rejection of the view that the function of philosophy is to propose basic principles of meaning and to construct a deductive system
Deductive system
A deductive system consists of the axioms and rules of inference that can be used to derive the theorems of the system....
by offering the consequences of these principles of meaning as a complete picture of reality. But this is, in fact, what Ayer does, in presenting the principle of verifiability as a criterion of meaningfulness for any empirical proposition.
According to Ayer, no proposition concerning 'matters of fact' can ever be shown to be necessarily true, because there is always a possibility that it may be refuted by further empirical testing. Logical certainty is possible only for analytic observations, which are tautologies, and not for empirical observations concerning 'matters of fact.'
Ayer explains that his radical empiricism is opposed to rationalism. Rationalism asserts that there are truths about the world that can be known by a priori reasoning, or independently of experience. According to the principle of verifiability, propositions about 'matters of fact' can be meaningful only if they are capable of being empirically verified.
Ayer agrees with, and elaborates on, Kant’s explanation of the distinction between analytic and synthetic judgments. According to Ayer, a proposition is analytic if its validity depends only on the definitions of the symbols it contains. A proposition is synthetic if its validity is determined by the facts of experience.
Analytic observations give us new knowledge, because they reveal unsuspected implications of our statements and beliefs. But analytic observations do not give us new knowledge of matters of fact, because they only tell us what is already known.
Truth as validation
Ayer defines truth as the criterion by which empirical propositions are validated. To say that a proposition is true is simply to assert it, and to say that a proposition is false is simply to assert a contradictory proposition. Thus, truth and falsehood are simply signs of assertion or denial of empirically verifiable propositions.In the same manner, assertions of value have meaning only insofar as they are verifiable. If an ethical or aesthetic judgment cannot be subjected to empirical testing, then it is meaningless. An empirical test may be practical or theoretical.
Value judgments
For Ayer, ethical or aesthetic judgments are subjective rather than objective, and cannot be demonstrated to be true or false. Ethical or aesthetic judgments express feelings, not propositions, and have no objective validity. Value-judgments are not analytic, and are not verifiable as 'matters of fact.'According to Ayer, when we argue about whether a value-judgment is right or wrong, we are really arguing about the empirical facts on which a value-judgment is based, or about the logical interpretation of empirical facts. We cannot argue about something that cannot be expressed as a proposition. We can only argue about something that can be analytically or empirically verified.
For Ayer, metaphysical statements, such as statements about transcendent reality, have no objective validity, and therefore are meaningless. Examples of this lack of meaning include statements about the existence or nonexistence of God. According to Ayer, such statements can be neither proven nor disproven, and cannot be validated or invalidated by empirical testing.
New take on philosophy
Ayer’s logical empiricism makes an important contribution to philosophy in that it provides a method of putting an end to otherwise irresolvable philosophical disputes. In Ayer's logical empiricism, philosophy is no longer seen as a metaphysical concern, nor as an attempt to provide speculative truths about the nature of ultimate reality. Instead, philosophy is seen as an activity of defining and clarifying the logical relationships of empirical propositions. In considering how to distinguish between a conscious man and an unconscious machine, Ayer also anticipates the development in 1950 of the Turing testTuring test
The Turing test is a test of a machine's ability to exhibit intelligent behaviour. In Turing's original illustrative example, a human judge engages in a natural language conversation with a human and a machine designed to generate performance indistinguishable from that of a human being. All...
to test a machine's capability to demonstrate intelligence (consciousness).
The principle of verifiability, however, may become a means to arbitrarily reject any abstract or transcendent concept, such as “truth,” “justice,” or "virtue." Such concepts are seen as having no literal meaning. Thus, Ayer’s viewpoint may become a radical scepticism. Ethics, aesthetics
Aesthetics
Aesthetics is a branch of philosophy dealing with the nature of beauty, art, and taste, and with the creation and appreciation of beauty. It is more scientifically defined as the study of sensory or sensori-emotional values, sometimes called judgments of sentiment and taste...
, and religion are all viewed as meaningless, as having no literal meaning. Ethical concepts are seen merely as expressions of feeling. Ethical or aesthetic concepts are seen as having no factual content, and therefore cannot be accepted as valid or invalid.
Ayer is careful to explain that the verification principle is a definition of meaning, and that it is not an empirical proposition. He admits that there are other possible definitions of meaning.
The most frequently-expressed reservation about the principle is whether it is itself verifiable; this was addressed in the fictional dialogue "Logical Positivism: a discussion". Ayer believed that it could be derived analytically from usual definitions of words like "understanding". He admitted that one could then ask for verification of that definition and then carry on into an infinite regress. Ayer considered the latter option to be simply not worth consideration, although philosophers like Donald Davidson
Donald Davidson (philosopher)
Donald Herbert Davidson was an American philosopher born in Springfield, Massachusetts, who served as Slusser Professor of Philosophy at the University of California, Berkeley from 1981 to 2003 after having also held teaching appointments at Stanford University, Rockefeller University, Princeton...
and Richard Rorty
Richard Rorty
Richard McKay Rorty was an American philosopher. He had a long and diverse academic career, including positions as Stuart Professor of Philosophy at Princeton, Kenan Professor of Humanities at the University of Virginia, and Professor of Comparative Literature at Stanford University...
have since used it to undermine the concrete view of language found in works like Language, Truth and Logic.
Release details
, the book has been printed in twelve editions. These include:- 1936, LondonLondonLondon is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
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, , 254 pages - 1946, LondonLondonLondon is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
: Victor Gollancz Ltd, , 160 pages - 1952, New YorkNew YorkNew York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
: Dover PublicationsDover PublicationsDover Publications is an American book publisher founded in 1941 by Hayward Cirker and his wife, Blanche. It publishes primarily reissues, books no longer published by their original publishers. These are often, but not always, books in the public domain. The original published editions may be...
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: Penguin BooksPenguin BooksPenguin Books is a publisher founded in 1935 by Sir Allen Lane and V.K. Krishna Menon. Penguin revolutionised publishing in the 1930s through its high quality, inexpensive paperbacks, sold through Woolworths and other high street stores for sixpence. Penguin's success demonstrated that large...
, ISBN 0140212000, 208 pages
External links
- Full text in PDF and other formats available from the Internet Archive
- Squashed Ayer -- a condensed and abridged version of Language, Truth and Logic
- Problems and Changes in the Empiricist Criterion of Meaning by Carl G. Hempel -- a critique of the principle of verification
- Two Dogmas of Empiricism by Willard van Orman QuineWillard Van Orman QuineWillard Van Orman Quine was an American philosopher and logician in the analytic tradition...
-- landmark criticism of logical positivism