I think that most likely in a century's time — if humanity survives that long and still goes in for philosophical debate — there will be a great deal of headscratching among philosophers as to why one of their number, Ludwig Wittgenstein, exerted such a massive influence on so many thinkers of an earlier generation. Also I would hazard a guess that much of this discussion will be carried on in cultural, historical, and psycho-biographical terms rather than through the kinds of "purely" conceptual exegesis that have characterised most treatments of his work up to now. (For a notable exception — a shrewdly perceptive study in the "life-and-times' mode — see Janik and Toulmin 1973.) The recent Cambridge Companion to Wittgenstein (Sluga and Stern [eds] 1996) is very much a state-of-the-art anthology that all the same shows a few signs of this incipient trend. For there are few things more remarkable about the period from 1960 to the present than the way in which Wittgenstein has routinely figured as a major — unignorable — point of reference for anyone who wants to venture some new line of argument or defend some established philosophical position against challenge from whatever quarter. Moreover, this compulsion has exercised a hold not only on true believers — Wittgenstein's heirs, disciples, and devoted exegetes — but also on those who register dissent yet still feel bound to run their case through the standard Wittgensteinian hoops. (See Norris 2000, for further discussion of some recent and particularly striking cases.) In what follows I shall try to explain this puzzling cultural phenomenon in a fairly objective or non-partisan manner.