The finest introduction to "the greatest philosopher of the 20th century" (New York Times Book Review), including the complete text of the Tractatus, The Blue and Brown Books, and On Certainty Major Works is the first single-volume English anthology of Ludwig Wittgenstein's important philosophical writings. Featuring the complete texts of Tractatus Logico-Philosophicus, The Blue and Brown Books: Studies for 'Philosophical Investigations, ' and On Certainty, this new collection selects from the early, middle, and later career of this revolutionary thinker, widely recognized as one of the most profound minds of all time. Wittgenstein contributed several groundbreaking ideas to philosophy, primarily in the foundations of logic, the philosophy of mathematics, the philosophy of language, and the philosophy of mind. "The greatest philosopher of the [20th] century ... Wittgenstein had an impact of extraordinary proportions. -- Colin McGinn, The New Republic