Vienna Circle

The claim

The verification principle: the meaning of a statement is the method of its verification. A sentence that no possible observation could bear on is not false but meaningless.

What it held

The Circle met on Thursday evenings from 1924, around the physicist-philosopher Moritz Schlick, and its members were mostly scientists and mathematicians rather than professional philosophers. That shows in what they wanted: not a new metaphysics but an end to metaphysics, and a unified language in which every science could state its results.

The programme has two halves. Analytic statements — logic and mathematics — are true by virtue of meaning and tell us nothing about the world. Synthetic statements are about the world and must be answerable to observation. Nothing falls outside those two categories, so the sentences of ethics, aesthetics and theology, having no observational content, express attitudes rather than state facts. Carnap made the point brutally about Heidegger, arguing that his sentences were not wrong but strictly nonsense.

The Circle also inherited a problem it never solved: the verification principle itself is neither analytic nor empirically verifiable, and therefore fails its own test.

How it argued

Logical analysis of the language of science, using the new formal logic of Frege and Russell to restate claims in a form where their empirical content, if any, becomes visible.

What it was arguing against

German idealism and the metaphysical tradition generally, Heidegger in particular, and any philosophy claiming knowledge of the world arrived at by pure reason.

Where it disagreed with itself

Whether the basic statements science rests on report private experience or public physical events — Neurath and Carnap argued for the latter against Schlick. Whether verification means conclusive verification or only confirmation, which was progressively weakened until little was left of it.

Common misconceptions

That logical positivism was refuted and abandoned. Its specific doctrines failed, but the standards of clarity, the seriousness about science and the formal methods became the working assumptions of analytic philosophy. And it was not politically detached: Neurath was a Marxist, and the group's manifesto was explicitly a programme for social reform.

How it began

Formed around Schlick's Vienna chair from 1924, drawing on Mach's empiricism, Wittgenstein's Tractatus — which several members read aloud line by line — and the new mathematical logic.

What became of it

Ended by politics rather than argument. Schlick was murdered on the steps of the university in 1936 by a former student, and the group's Jewish and left-wing members scattered to Britain and the United States, where their programme took root in the very departments that later dismantled it.

Lasting influence

Analytic philosophy is largely its descendant, including the parts that reject it. Quine's attack on the analytic-synthetic distinction and Popper's substitution of falsifiability for verification are both arguments within a framework the Circle established.

Why it still matters

The demand that a claim specify what would count against it remains the most useful single question in argument, whatever became of the theory of meaning it came from.

Put another way

A building inspection that condemns most of the house, then discovers the inspector's own standard will not hold up either.

Where to start

Ayer, then the manifesto. Ayer is clearer than he is careful, which is exactly what you want first.

The surprising bit

Wittgenstein, whose Tractatus the Circle treated as founding, refused to join it, disliked what they made of him, and preferred to read them Rabindranath Tagore's poetry with his back to the room.

In their own words

Connections

Opposed by

German Idealism

Influenced

Ordinary Language Philosophy, Pittsburgh School (Sellarsian Realism)

The verdict

It asked the right question about meaning, gave an answer that could not survive being applied to itself, and changed philosophy anyway.

Sources

• Stanford Encyclopedia of Philosophy