He poured scorn on Edward Said's foolish fantasies about the role of literature in imperialism. Said accused Gellner of an "obsessive revulsion for Islam" and of lacking the languages to do proper fieldwork. In fact, Gellner spoke Berber fluently, but he ignored the ad hominem insults, pointing out that the best scholarship on Oriental societies came from Westerners, including colonial administrators, rather than Said's ideological confrères. Although Said denied his own political correctness, the charge stuck.

Gellner's view of Muslim societies may, indeed, prove to be his most lasting contribution. What struck him most forcibly was the fact that Islam had not only survived but flourished in the modern world, having proved immune to the secularisation of the Judaeo-Christian West. In his posthumous ly published study, Nationalism, Gellner argued that, while the inevitability of secularisation might be valid for other civilisations, "in Islam, it is not true at all". Indeed, Islam had proved more resilient than its supposedly more modern ideological rival, Marxism. Nor did the other great European ideological export, nationalism, replace Islam as an agency of development. Gellner attributed this to the fact that Islam was "modern, but not too modern". 

What was Gellner's solution to the threat posed by Islam? He believed passionately in what his teacher Karl Popper had called the open society, and he preferred to call civil society, but by which both men meant the liberal values embodied in the Britain that had offered them refuge. "I am not a relativist," he wrote. "The existence of a culture-transcending truth seems to me the most important single fact about the human condition." 

But he was pessimistic about preaching the superiority of Western values to Islamic or other fundamentalists, because "the nature of our choice prevents us from proving its pre-eminent merit. We have to live with this." After the first Gulf War, Gellner was disappointed that an "unholy alliance" to defend Western civilisation had not emerged. Subsequent events, however, suggest that his pessimism was justified.