(a) "We should look not to an ideal language which derives its meaning from facts and has a precise logical structure but…

(a) Wittgenstein: from ideal language to language-games

In the Tractatus Logico-Philosophicus, early Wittgenstein constructed a truth-conditional, atomistic model of language. Central to this was the Picture Theory of meaning: a proposition is a logical picture of reality. A strict structural isomorphism exists between language and the world—names correspond to simple objects, elementary propositions to atomic states of affairs, and complex propositions to facts. Language has an underlying logical syntax that determines the limits of thought; what can be stated clearly belongs to natural science, whereas ethics, aesthetics, and metaphysics cannot be spoken of factually but only shown (the saying versus showing distinction). The early view assumed a single, precise, ideal logical structure beneath everyday speech.

Wittgenstein later abandoned this essentialism in Philosophical Investigations, recognizing that language is not a static formal calculus mirroring atomic facts. Instead, he argued that "the meaning of a word is its use in the language" (PI 43). Language consists of an indefinite, evolving multiplicity of rule-governed activities termed language-games (PI 23), embedded in human forms of life (Lebensformen). Rejecting the search for a single universal essence of language, he introduced *family resemblances*—overlapping networks of similarities, as seen in games. Through the Private Language Argument, he demonstrated that language is inherently social and normative; subjective mental ostension cannot establish linguistic rules because sensations lack public criteria for correctness. Philosophy therefore ceased to be the construction of an ideal language and became the therapeutic description of ordinary usage. This is exactly the shift the quoted statement records: meaning is no longer fixed by a logical correspondence with facts but found empirically in the ways a language is actually used.

(b) Verification theory: logical positivism and the strong–weak distinction

Logical Positivists of the Vienna Circle (Carnap, Schlick) and A.J. Ayer formulated the Verification Principle to establish a demarcation between cognitively meaningful discourse and metaphysical pseudo-propositions. A synthetic proposition is cognitively significant if and only if it is empirically verifiable; otherwise, it must be tautologous (analytic) or literally nonsensical.

Ayer distinguished between two senses of verifiability: Strong Verifiability: A proposition is verifiable in the strong sense if and only if its truth can be conclusively established by direct empirical observation. Weak Verifiability: A proposition is verifiable in the weak sense if empirical observation can render it probable or provide confirmatory evidence for it.

The Positivists were forced to shift from strong to weak verifiability because strong verification rendered universal scientific laws (e.g., "all metals expand when heated") and historical statements meaningless, as no infinite or past series of observations can be conclusively verified. However, weak verification faced fatal challenges: Alonzo Church and Carl Hempel showed that liberalizing the criterion allowed any nonsensical statement to become indirectly verifiable when conjoined with a suitable hypothesis. Furthermore, Willard Van Orman Quine demonstrated the failure of verificationist reductionism by establishing that empirical claims face the tribunal of experience as an interconnected web of belief rather than as isolated sentences. Crucially, the principle was self-refuting, as the criterion of verification is itself neither analytic nor empirically verifiable.

(c) Moore's refutation of idealism

In The Refutation of Idealism (1903), G.E. Moore attacked the foundational idealist doctrine that esse est percipi (to be is to be perceived). Moore analyzed sensations into two distinct, irreducible elements: the act of consciousness (which is identical in all experiences) and the specific object of that consciousness (such as blue or green).

Idealists like Berkeley conflated the act of awareness with the object perceived. Moore explained that consciousness is diaphanous (transparent): when we try to introspect consciousness itself, we look right through it and perceive only its object (the color blue). Because consciousness is identical whether one experiences blue or green, the object of sensation must be distinct and independent from the subjective awareness of it. Experiencing blue is an intentional relation between the mind and an external, non-mental quality.

Moore’s act-object distinction grounded his commonsense realism, later defended through his famous ostensive demonstration in Proof of an External World ("here is one hand... and here is another"). Critics replied that the argument shows only that the act and the object are distinguishable in thought, not that the object exists unperceived, and Moore himself later called the 1903 paper confused. Its lasting effect was to make the act–object analysis of perception central to early analytic realism.