SEEING THE INVESTIGATIONS ‘IN THE RIGHT LIGHT’

In the preface to the Philosophical Investigations, Wittgenstein wrote the following about the relationship between that book and his previous work:

This raises a question that confronts every reader of the Philosophical Investigations: what was Wittgenstein's ‘old way of thinking’, and what is the relationship between his ‘old thoughts’ and the ‘new ones’? Unfortunately, while there are a number of short and simple answers to be found in philosophical encyclopedias, none of them is satisfactory. The conventional wisdom is that there were ‘two Wittgensteins’, the ‘early Wittgenstein’ who wrote a logico-philosophical treatise, and the diametrically opposed ‘later Wittgenstein’, the author of the Philosophical Investigations. At first sight, the two books look very different, and the preface to the Philosophical Investigations speaks of Wittgenstein's recognition of ‘grave mistakes in what I wrote in that first book’ (PI, ⅷ/ⅹ).

The Tractatus is forbiddingly formal and presupposes knowledge of Frege's and Russell's work on modern logic. Because every proposition in the book is numbered, and the book is so short, it looks like an analytical table of contents for a much longer book.