Conservatism and its modernising, anti-traditionalist rivals, liberalism and socialism, are the most influential political philosophies and ideologies of the post-Enlightenment era. Conservatives criticise their rivals for making a utopian exaggeration of the power of theoretical reason, and of human perfectibility. Conservative prescriptions are based on what they regard as experience rather than reason; for them, the ideal and the practical are inseparable. Most commentators regard conservatism as a modern political philosophy, even though it exhibits the standpoint of paternalism or authority, rather than freedom. As John Gray writes, while liberalism is the dominant political theory of the modern age, conservatism, despite appealing to tradition, is also a response to the challenges of modernity. The roots of all three standpoints “may be traced back to the crises of seventeenth-century England, but [they] crystallised into definite traditions of thought and practice only [after] the French Revolution” (Gray 1995: 78).