Published a century ago this spring, the Tractatus is certainly one of the oddest books in the history of logic, structured in an unconventional outline of unspooling pronouncements offered without argument, as well as a demonstration of philosophy’s basic emptiness, and thus the unknowability of reality. All great philosophers claim that theirs is the work that demolishes philosophy, and Wittgenstein is only different in that the Tractatus actually achieves that goal.