[Old jottings from my journal.] Lenin’s Materialism and Empirio-Criticism, from the selections I’ve read so far, is sensible. (That isn’t the academic consensus, but what do you expect from philosophers? He’s a Commie, after all.) Here’s one of his briefer summaries of George Berkeley’s thought: “Let us regard the external world, nature, as a ‘combination of sensations’ evoked in...