In 1929 Wittgenstein began to work on the first philosophical manuscripts he had kept since completing the Tractatus Logico-Philosophicus in 1918. The impetus for this was his conviction that the logic of the TLP was flawed: it was unable to account for the fact that a proposition that assigns a single value on a continuum to a simple object thereby excludes all assignments of different values to the object . Consequently Wittgenstein's "atomic propositions" could not be logically independent of one (...) another. ;Initially he thought he could replace the "logically perfect language" of the TLP with a "phenomenological language" in which experiential propositions about various "spaces" would form systems. The system described by a phenomenological language would be independent of the one described by ordinary "physicalistic" language; the physical "world" was known only by inference from the phenomenological. But he soon realized there was a fundamental error in this conception: phenomenology has to describe the same world as physics or it fails to provide a foundation for it. This suggests that there is only one world, and one language with two different modes of expression. Wittgenstein's now comes to his fundamental insight: ordinary language is biased towards the description of physical objects and their relations, but it is our only method of expressing phenomenological or abstract concepts. Failure to recognize this difficulty leads to the misapplication of physicalistic concepts, i.e., to grammatical errors. ;This insight had the following impact: the task of philosophy is not to invent logical or phenomenological languages, but to understand the grammar of ordinary language; the notion of a language of pure experience was itself connected with a false, physicalistic idea of the soul as an observer of a private world; the conception of analysis that had guided philosophy since Frege was based on a misused metaphor taken from the grammar of physics: the analysis of an object into its parts or chemical constituents. These ideas reach their ultimate expression in Wittgenstein's Philosophical Investigations. Thus his "later" work actually begins with these 1929--30 manuscripts. (shrink)