There can be no doubt that careful study of Wittgenstein’s Nachlass sheds great light upon the meaning of many of his otherwise baffl ing remarks in the Investigations . In numerous cases, it defi nitively settles important interpretative controversies concerning what he meant by some critical expression (e.g., “Praxis”) or what he meant by some individual remark (e.g., philosophy “leaves everything as it is” (§124)). It also sheds much light upon the development of Wittgenstein’s ideas over the sixteen years of work on his second masterpiece. For not everything changed at once, and progress in achieving clarity developed now on one front, now on another. Moreover, in some cases different ideas were tried out and then abandoned (e.g., the symptom/hypothesis relation, the methodological solipsism of the Philosophical Remarks , the distinction between “‘I’ as subject” and “‘I’ as object” in the Blue Book), and various routes through the landscape were found to be dead-ends.