The nineteenth century witnessed a conservative reaction against the Enlightenment and the ideals of the French Revolution, but it was also a period in which philosophical radicalism flourished in both politics and religion. Radical attacks on religion and on the foundations of the political order perhaps even invite questions about the basis of morality itself. Antimoralist stances were taken by philosophers and literary artists before the nineteenth century, such as in the works of Rabelais and Diderot. But it was not until the nineteenth century that we find systematic attacks on morality derived from central themes and theses in the philosophical tradition.

Friedrich Nietzsche is probably the best-known nineteenth-century antimoralist, but he was neither the first nor the most radical. The appeal of radical antimoralism seems to have declined in the twentieth century, perhaps due to the increasing need people felt to appeal to moral standards in opposing totalitarianism and war. To reject morality wholesale, most of us now think, is to leave ourselves in some ways defenseless against some of the worst abuses of political, economic, and military power. But traces of nineteenth-century antimoralism clearly remain in modern culture: our attitudes toward sexual morality have changed a great deal. The moralistic rhetoric we find in many older moral philosophers (e.g., in Kant) now either offends our ears or else provides opportunities for condescending humor. Terms like ‘duty’ and ‘virtue’, in today’s discourse, are either suspect or ridiculous. Only social conservatives are left to express outrage (often the hypocritical outrage characteristic of traditional religious morality) at all the social tendencies they lump together under the heading of ‘relativism’. Fragments of nineteenth-century antimoralism, at least, occasionally find expression in philosophy, in both the postmodernist and analytical traditions.