The Man Who Solved Philosophy, and Then Solved It Again, Differently

There are not many philosophers who fundamentally revolutionized the discipline twice, from opposite starting points. Ludwig Wittgenstein (1889-1951) is essentially the only one.

The first Wittgenstein, the author of the Tractatus Logico-Philosophicus (1921), believed he had solved the fundamental problems of philosophy. Not made progress on them. Solved them. His solution: philosophical problems arise from misunderstandings about the logic of language. Language works by picturing facts: a sentence has the same logical form as the state of affairs it describes, like a map that has the same structure as the territory it represents. The limits of language are the limits of what can be said at all. Metaphysics, ethics, aesthetics, the meaning of life: none of these can be stated as propositions, because there are no facts for them to picture. They show themselves in the structure of language and the world, but they cannot be said. The famous last line of the Tractatus: "Whereof one cannot speak, thereof one must be silent."

This was enormously influential on the Vienna Circle logical positivists, who used it to declare metaphysical statements meaningless. Wittgenstein himself did not draw that conclusion: he thought what could not be said was the most important thing, which was why it had to be shown rather than stated. The Tractatus ends not with a dismissal of what cannot be said but with a kind of reverent gesture toward it.

Then Wittgenstein spent a decade away from philosophy, convinced he had finished it. He taught elementary school in rural Austria, designed a building for his sister, and eventually returned to Cambridge in 1929 with growing doubts about his first work.

What changed? In part, it was a remark by the Italian economist Piero Sraffa, who responded to Wittgenstein's claim that language and reality must share the same logical form by making a Neapolitan gesture (brushing his chin with his fingers in a dismissive flick) and asking: what is the logical form of that? The question punctured something in Wittgenstein's picture theory. Language does not only picture facts. It does an enormous variety of things: giving orders, telling stories, playing games, greeting people, joking, swearing, praying. And the meaning of language in all these uses is not determined by its correspondence to some logical form but by how it is actually used in human life.

This insight generated the second Wittgenstein, whose major work, the Philosophical Investigations (published posthumously in 1953), is among the most important philosophical texts of the 20th century and reads like nothing else in the philosophical canon: a series of numbered observations, questions, examples, and thought experiments that circle around a set of interconnected problems rather than marching through an argument. It is philosophical writing that does philosophy rather than describes it.