On the received reading of Ludwig Wittgenstein's Philosophical Investigations, the book contains an argument purporting to show the impossibility of a private language. There has been a lively debate, however, on how the relevant notion of a private language is to be understood, and what considerations should be taken to rule it out. Some have understood Wittgenstein to mean that a language must be something that several speakers actually share, while others take him to mean that a language must be something that they could, in principle, share. Or, differently put, on one view, speaking a language presupposes the actual existence of a linguistic community upholding certain shared standards of meaning and correctness, while on the other view, it only presupposes that such a community might have existed. These views have come to be known as the ‘community view’ and the ‘solitary speaker’ view, respectively. Furthermore, supporters of the community view tend to think that the discussion about privacy holds a central place in Wittgenstein's later philosophy, whereas those who support the solitary speaker view usually see its bearings as limited to the issue of the privacy of experience.

Most of those who have participated in this debate have not simply taken an exegetical interest in it: they usually regard the view they favour, not only as the correct interpretation of Wittgenstein, but as the correct view on the matters at hand. In fact, the questions of what we are to think and what Wittgenstein must have meant (as is often the case in discussions of Wittgenstein's later philosophy) are mostly not kept separate. I do not wish to insist on the separation of these questions: while the fact that Wittgenstein held a certain view is good reason for taking it into serious consideration, what matters in the end is not what Wittgenstein actually meant to say, but what, if anything, we may learn from his remarks.

Wittgenstein's main concern in philosophy was to change our perspective on philosophical problems, and his remarks on privacy and meaning seem to me to have been central to that effort. While there are serious objections to the community view in its traditional form, I hope to make it clear that the emphasis on how the sense of things said is connected with human interaction is crucial to the perspective he was advancing.