Democracy is modern, since it is only within recent times that the general diffusion of knowledge has been possible. The invention of printing, by making possible a cheap popular literature, contributed more than any other one fact to the intellectual and moral awakening which marks the beginning of modern times. The introduction of printing, however, did not find a democratic literature ready for general distribution, or the people ready for its appearance. A long period of slow preparation followed, during which the masses were being educated. Moreover, it is only within recent times that governments would have permitted the creation and diffusion of a democratic literature. For a long time after printing was invented the ruling classes carefully guarded against any use of the newly discovered art that might be calculated to undermine their authority. Books containing new and dangerous doctrines were rigorously proscribed and the people carefully protected from the disturbing influence of such views as might shake their faith in the wisdom and justice of the existing social order.[198] It is perhaps fortunate for the world that the political and social results of printing were not comprehended at the time of its introduction. Had the ruling classes foreseen that it would lead to the gradual shifting of political power from themselves to the masses, it is not unlikely that they would have regarded it as a pernicious innovation. But, as is the case with all great inventions, its full significance was not at first understood. Silently and almost imperceptibly it paved the way for a social and political revolution. The gradual diffusion of knowledge among the people prepared them for the contemplation of a new social order. They began to think, to question and to doubt, and thenceforth the power and prestige of the ruling classes began to decline. From that time on there has been an unceasing struggle between the privileged few and the unprivileged many. We see it in the peaceful process of legislation as well as in the more violent contest of war. After each success the masses have demanded still greater concessions, until now, with a broader outlook and a larger conception of human destiny, they demand the complete and untrammeled control of the state.