Positivism, not just an “ivory tower” philosophy, was a major force in the social, political, and educational life of Mexico during the last half of the nineteenth century. Once colonial conservatism had been conquered, the French Intervention ended, and Maximilian of Hapsburg executed, reformers wanted to create a new national order to replace the Spanish colonial one. The victorious liberals strove to achieve “mental emancipation,” a kind of second independence, which would abolish the habits and customs imposed on Mexicans by three centuries of colonialism. At this singular moment in Mexican history, positivism was offered as an extraordinary means and pathway to a new order. The next stage was the education of the Mexican people in this liberal philosophy and their incorporation into the process of development achieved by modern nations. Leopoldo Zea traces the forerunners of liberal thought and their influence during Juárez’s time and shows how this ideology degenerated into an “order and progress” philosophy that served merely to maintain colonial forms of exploitation and, at the same time, to create new ones that were peculiar to the neocolonialism that the great nations of the world imposed on other peoples. Zea examines the regime of Porfirio Díaz and its justification by the positivist philosophers of the period. He concludes that the conflict between exploited social groups, on the one hand, and foreign interests and a middle class on the margin of an oligarchy, on the other, brought about the movement known as the Mexican Revolution.