 In the 1930s and 1940s Wittgenstein conducted seminars at Cambridge, developing most of the ideas that he intended to publish in his second book, Philosophical Investigations. These included the turn from formal logic to ordinary language, novel reflections on psychology and mathematics, and a general skepticism concerning philosophy’s pretensions. In 1945 he prepared the final manuscript of the Philosophical Investigations, but, at the last minute, withdrew it from publication (and only authorized its posthumous publication). For a few more years he continued his philosophical work, but this is marked by a rich development of, rather than a turn away from, his second phase. He traveled during this period to the United States and Ireland, and returned to Cambridge, where he was diagnosed with cancer. Legend has it that, at his death in 1951, his last words were “Tell them I’ve had a wonderful life” (Monk: 579).