The attribution of a revolutionary role to philosophy is normally taken to be a characteristic of the modern epoch. Modernity, understood very generally as the age initiated approximately by the Enlightenment, is thus conceived as a revolution against the 'grand alliance' between classical thought and Christian faith. In this view, the history of modern philosophy is a series of explications of the revolutionary content of the Enlightenment. This revolution assumes a special form in the nineteenth century. Whether one calls it decadence, or the decisive preparation for the millennium, there is an obvious bifurcation of revolutionary energy. The main force of scientific rationalism, in its practical embodiment as bourgeois society, is attacked by two counterrevolutionary armies, one on the left and one on the right. The commanders of these counterrevolutionary armies are, of course, Marx and Nietzsche. The modern age is widely perceived as an epoch of revolution and counterrevolution.