There are three main topics in the Philosophical Investigations: (i) a critique of what Wittgenstein regards as the dominant referential conception of meaning, and a proposal to replace it with a conception in which to use language meaningfully is to master a certain kind of social practice; (ii) a critique of the previously dominant conception of philosophical analysis, and the substitution of a new conception of analysis to play the central role in philosophy; and (iii) the development of a new philosophical psychology in which what appear on the surface to be sentences that report private sensations and other internal mental events or states are viewed as having meanings which license their assertion on the basis of public criteria having to do with behavior and external circumstances.