A.J. Ayer, Language, Truth and Logic (1936)



Preface to the First Edition



Accepts Hume's position (31)


o     Relations of ideas

-- A priori propositions of logic and pure mathematics

-- Necessary, because analytic

o  Cannot be confuted by experience because make no assertion about empirical world

o     Simply record our determination to use symbols in a certain fashion


o     Matters of fact

-- Hypothetical propositions about empirical state of affairs

-- Probable and require verification

o     Must have possible sense-experience relevant to determination of truth or falsity

o     Make sense but can never be apodictic


Radicalizes Hume's position


o     Locus of metaphysical propositions

-- Ayer does not see as possible on level of relations of ideas

-- Presents as on level of hypothesizes, which makes them empirical (i.e., factual) claims requiring verification


o     Status of metaphysical propositions

-- Criteria of sense:  either empirically verifiable or analytically tautological

--- If propositions neither empirically verifiable nor analytically tautological, they are metaphysical

o     Neither true nor false

o     Literally senseless (early Wittgenstein would say non-sense)



The Function of Philosophy (32)


o     Elimination of prior role

-- Not present speculative truth that competes with hypotheses of science

-- Not pass a priori judgment on validity of scientific theories


o     Limitation on current role

-- Clarify the propositions of science

o     Exhibit logical relationships

o     Define symbols that occur in them

-- No basis for conflicting philosophical schools

o     No dissent allowed

o     Orthodoxy imposed




The Elimination of Metaphysics (33)


Critique of Metaphysical Knowledge


o     Metaphysics claims knowledge of reality transcending world of science & common sense


o     Ayer assumes premises of metaphysical propositions were deduced

-- Many metaphysicians claim intuition of first principles

-- If deduced, Ayer assumes based on evidence from senses

o     Ayer does not consider evidence from understanding

o     Ayer does not allow reason to have synthetic function, only analytic

-- Cannot infer super-empirical properties from empirical premises


o     Response to claim of intellectual intuition

-- Even if shown they use empirical premises, metaphysicians claim their super-empirical inferences not necessarily false simply because conclusions not follow from premises

-- Ayer shifts to criticism of nature of metaphysical statements per se

o     Ayer's non-verifiable claim:  "no statement which refers to a 'reality' transcending the limits of all possible sense-experience can possibly have any literal significance" (34)

o     Ayer equates literal significance with empirical reference



Reflections on Kant


o     Kant rejected transcendent metaphysics

-- Rejected as factual impossibility

-- Ayer rejects as logical impossibility as well, contra Kant


o     Critique of Kant

-- Kant assumes we can assert reality of things beyond sense-experience

-- Ayer claims this assertion requires Kant to have succeeded in going beyond the boundary

o     If locked into experience, locked into total phenomenalism

o     Not only is thought of such a super-empirical reality non-factual but also it is illogical

q      Ayer does not address whether illogical like a round square

q      Ayer does not address whether illogical like a mermaid

q      Ayer does not address whether illogical only from phenomenalistic assumptions

¤      Does not consider transcendental deduction that noumenal lies behind phenomenal

¤      If transcendental deduction possible, only constraint for human cognition is non-contradiction in asserting one of the antinomies of noumenal possibility as thinkable and practical


Basis for rejecting metaphysics


o     Not from psychological hypothesis on constitution of human mind (35)


o     "From the rule which determines the literal significance of language"

-- Metaphysics "produces sentences which fail to conform to the conditions under which alone a sentence can be literally significant"

-- Verification principle:  a proposition is factually significant if and only if one knows how to verify it

o     Transcendent metaphysics does claim factual

o     Transcendental metaphysics does not claim factual

q      Genuine rejection cannot be based on verification

q      If reject must do so by undercutting synthetic a priori judgments of reason

¤      Critique tends to focus on propositions

¤      Judgment not restricted to same criteria as propositions


o     Defense of weak verification principle (36)

-- Ayer rejects conclusive verification

-- Ayer rejects conclusive confutation


o     Philosophy must distinguish itself from metaphysics (41)


o     Emergence of metaphysics from grammatical confusion

-- In language, we predicate sensible properties to a thing

-- Metaphysics assumes the thing itself is distinct from predications

o     Only language distinguished the thing from its appearance

o     Thing is not distinct from its appearance

¤ Ayer himself makes an inference about things on the basis of language

¤ Ayer himself makes a metaphysical claim with assertion of phenomenalism


Status of metaphysics


o     Some see metaphysician as misplaced poet (44)


o     Ayer rejects

-- Sentences of poets generally do have literal meaning

-- Sentences of metaphysics have no literal meaning