Abstract

In both the Tractatus and the Investigations, Wittgenstein claimed that the aim of philosophy is to achieve clarity: to see clearly the logic or grammar of our language. However, his view of clarity underwent an important change, one of many changes that led Wittgenstein to write, in the preface to the Investigations, that his new ideas “could be seen in the right light only by contrast with and against the background of my old way of thinking.” I argue that certain “grave mistakes” of the Tractatus were due to an idealised conception of clarity, and that a revised understanding of clarity is one of the main achievements of the Investigations. In the Tractatus Wittgenstein wrongly assumed that when we see language clearly, what we see will be determinate, exact, and complete. In the Investigations he realised that when we see language clearly we cannot specify in advance whether what we see will be determinate or vague, exact or inexact, complete or incomplete. I characterise this insight as a truism: when we see clearly, what we see might not be clear. Wittgenstein wants the Tractatus to serve as a warning to the reader of the Investigations; his own past mistakes are instructive and this is why we should read the Investigations against the background of his old way of thinking.