ON the one hand the development of the physical sciences, the discovery of Newton's principle which made it possible to found on a single law a complete science of nature, and the conception of the hope of discovering an analogous principle capable of serving for the establishment of a synthetic science of the phenomena of moral and social life; on the other hand a profound crisis in society, a crisis which was itself due in part to the development of science and to the progress of its practical applications, a crisis which called for transformations of the judicial, economic, and political régimes and gave rise to schemes for reform and to reformers without number, a crisis, finally, which demanded a single principle capable of uniting into a single theoretic whole so many scattered notions: -- these are the general causes of the formation of Philosophical Radicalism. They had been at work since the eighteenth century; but the Utilitarian doctrine had not as yet assumed its definitive shape. Bentham, who was already the author of a complete code, a View of a Complete Body of Legislation, did not become famous as a reformer of the science of law till the early years of the following century. Twenty-five years of crisis come between the two extreme periods of his life: the one previous to 1789 when, still unknown, he was a philosopher of the eighteenth century, in the style of Voltaire, Hume, Helvetius and Beccaria; the other subsequent to 1815, when he was the theorist of a party of democratic agitation organised according to the methods peculiar to the nineteenth century.
It is therefore necessary in order to describe the formation of Philosophical Radicalism first to explain the original state through which the Utilitarian doctrine passed in the eighteenth century. How did it come about that Bentham was destined by his own genius, and by circumstances more or less special, eventually to be the head of the school? The circumstances which explain this fact are complex and various; and the progress of the doctrine did not come about in all points with the same speed or according to the same law.