The Vienna Circle, like the Bloomsbury Group, came in for a lot of criticism, especially from those not invited to their parties. Cliquish, precious, arrogant, excessively convinced of their own central place in the scheme of things, it was said. All true. But both groups included several geniuses and did achieve something outstanding.

Although the two groups spoke different languages and found themselves on opposite sides in the Great War, they were closely associated with two men crucial to both. Bertrand Russell, later in and out of the beds of Bloomsbury and busy writing potboilers on marriage and morals, had in 1910 co-authored Principia Mathematica, a massive book on symbolic logic and the foundations of mathematics which the Vienna Circle took as a model for their project of exactitude in thinking. From the other direction, Ludwig Wittgenstein brought his idiosyncratic version of Viennese thought to Cambridge and became the dominant figure in mid-twentieth-century British philosophy.

German scientists had a near-compulsory immersion in philosophy in their upbringing.

The essential idea of the Vienna Circle was that everything should be approached scientifically. Logic, precision, mathematics were in, anything smacking of “metaphysics” was out. What that meant is not what it would mean in an Anglophone culture. In English, “science” means the investigation of the causes of things through inductive reasoning from observations, generally free from any fanciful philosophical overhead. But a fundamental difference between Anglophone and German-speaking cultures was that German scientists had a near-compulsory immersion in