Many admirers of Wittgenstein’s Philosophical Investigations and of Strawson’s Individuals have taken the theme of both books to be an analysis of philosophical skepticism and their distinctive contribution to be a new way of criticizing the skeptic. This new way is summed up in a familiar passage from Strawson:

In an earlier period of analytic philosophy, the standard reply to the skeptic had been of the phenomenalistic Hume–Berkeley type. That is, the skeptic’s suggestion that what were usually taken to be material objects or other persons might merely be the content of his own consciousness – his own representations – was met with the reply that to have such-and-such representations just was to be seeing a material object or another person. This if-you-can’t-beat-him-join-him strategy, however, always (a) got shaky when “was” was questioned (did it mean “entailed”? “confirmed”?) and (b) had an unpleasant air of idealism about it, no matter how much it was claimed to be a “logical” rather than a “metaphysical” point. So when, on the heels of Austin’s attack on “the ontology of the sensible manifold,” Strawson revived the distinctively Kantian anti-idealist thesis that “inner experience requires outer experience,” the shift in strategy was welcomed. Strawson’s points about persons and material objects fitted together nicely with Wittgenstein’s “private-language argument” to suggest that the skeptics’ notion of a world of pure experience – a world containing nothing but representations – did not really make sense.