"The emergence of Einstein as a world figure in 1919 is a striking illustration of the dual impact of great scientific innovators on mankind. They change our perception of the physical world and increase our mastery of it. But they also change our ideas. The second effect is often more radical than the first. The scientific genius impinges on humanity, for good or ill, far more than any statesman or warlord. Galileo's empiricism created the ferment of natural philosophy in the seventeenth century which adumbrated the scientific and industrial revolutions. Newtonian physics formed the framework of the eighteenth-century Enlightenment, and so helped to bring modern nationalism and revolutionary politics to birth. Darwin's notion of survival of the fittest was a key element in both the Marxist concept of class warfare and the racial philosophies which shaped Hitlerism. Indeed the political and social consequences of Darwinian ideas have yet to work themselves out, as we shall see throughout this book. So, too, the public response to relativity was one of the principal formative influences on the course of twentieth-century history. It formed a knife, inadvertently wielded by its author, to help cut society adrift from its traditional moorings in the faith and morals of Judeo-Christian culture."