A work of philosophical genius according to some, a work of art according to others. Ludwig Wittgenstein’s Tractatus Logico Philosophicus was published 100 years ago, in 1921. It’s a book that according to its own philosophy of language, is mostly nonsense. Language, according to the strict logic of the Tractatus, is meaningful only when it functions as a picture of the world, a crystal-clear reflection of the structure of reality. It follows that most philosophical questions are meaningless and have to be condemned to silence. The Tractatus went on to influence philosophical movements like the logical positivists, but its lasting significance remains a matter for debate. Leading Wittgenstein scholars offer their views on the question of its legacy today.