“Philosophy,” the early German Romantic writer Novalis remarked, “is homesickness”: the desire to be at home everywhere in the world. If that’s right, then surely philosophers should also want to be architects—or at any rate, to build houses for themselves.

And yet, as far as I know, no great philosopher has ever successfully made the transition from the armchair to the drafting table. In fact, the only one who even attempted anything remotely like it was Ludwig Wittgenstein, who in the middle of the 1920s helped supervise the construction of a modernist townhouse in Vienna for his sister Margrethe. Technically, the architect on the project was Paul Engelmann, a friend of Wittgenstein’s who had been a student of the pioneering modernist Adolf Loos. But so particular was Wittge...