Does on Certainty Represent the Third Wittgenstein? A Critical Evaluation

In addition to Tractatus Logico-Philosophicus (1921) and Philosophical Investigations (1951), Wittgenstein left a collection of notes. Some of his students have published edited versions of these remaining notes under various titles. One of the latest of these collections came to the market in 1969 under the title of "On Certainty". In this book, Wittgenstein discusses the issue of certainty from an epistemological point of view. He rejects scepticism and argues that certainty belongs to the category of non-epistemological concepts. And he adds that certainty, though meaningless, nevertheless is necessary for the formation of knowledge. A group of commentators, including Rom Harre´ and Moyal-Sharrock, have referred to this new approach of Wittgenstein as the Third Wittgenstein. The purpose of the present paper is to critically examine the development of Wittgenstein's thought from Tractatus to On Certainty with respect to the notion of certainty to show that contrary to the claims of philosophers like Harre´and Moyal-Sharrock, the Wittgenstein of On Certainty is not a new Wittgenstein, and that the basis of his discussions concerning scepticism and certainty and their meaninglessness could be traced back to his views in Tractatus and Investigations, and in particular, his discussion of private language and its denial.