This book on the Tractatus is lauded, on the dust jacket, as “the first to make sense of the work as a whole.” Both new and veteran readers of Wittgenstein, we are told, “will benefit from Donald Peterson's exceptionally clear explication and commentary on this crucial work of the twentieth century.” Grand claims, these; and both of them arguably false. To be sure, Peterson writes well; and there are parts of the book—especially those dealing with Wittgenstein's Grundgedanke (chap. 4) and Notation (chap. 7)—from which all will benefit. But the clarity of his writing can beguile neophyte and incautious veteran alike into supposing that the ideas he explicates are Wittgenstein's rather than the author's own.