The paradox of tolerance is a philosophical concept suggesting that if a society extends tolerance to those who are intolerant, it risks enabling the eventual dominance of intolerance; thereby undermining the very principle of tolerance. This paradox was articulated by philosopher Karl Popper in The Open Society and Its Enemies (1945), where he argued that a truly tolerant society must retain the right to deny tolerance to those who promote intolerance. Popper posited that if intolerant ideologies are allowed unchecked expression, they could exploit open society values to erode or destroy tolerance itself through authoritarian or oppressive practices.

The paradox has been widely discussed within ethics and political philosophy, with varying views on how tolerant societies should respond to intolerant forces. John Rawls, for instance, argued that a just society should generally tolerate the intolerant, reserving self-preservation actions only when intolerance poses a concrete threat to liberty and stability. Other thinkers, such as Michael Walzer, have examined how minority groups, which may hold intolerant beliefs, are nevertheless beneficiaries of tolerance within pluralistic societies.

This paradox raises complex issues about the limits of freedom, especially concerning free speech and the protection of liberal democratic values. It has implications for contemporary debates on managing hate speech, political extremism, and social policies aimed at fostering inclusivity without compromising the integrity of democratic tolerance.