The true interest of all these details about a mere book lies in the immense significance of the movement of political ideas and forces to which they belong. The true interest of all history lies in the spectacle which it furnishes of the growth and dissolution, the shock and the transformation, incessantly at work among the great groups of human conceptions. The decree against the Encyclopaedia marks the central moment of a collision between two antagonistic conceptions which disputed, and in France still dispute, with one another the shaping and control of institutions. One of these ideas is the exclusion of political authority from the sphere and function of directing opinion; it implies the absolute secularisation of government. The rival idea prompted the massacre of St. Bartholomew, the dragonnades, the revocation of the Edict of Nantes, and all the other acts of the same policy, which not only deprived France of thousands of the most conscientious and most ingenious of her sons, but warped and corrupted the integrity of the national conscience. It is natural that we should feel anger at the arbitrary attempt to arrest Diderot's courageous and enlightened undertaking. Yet in truth it was only the customary inference from an accepted principle, that it is the business or the right of governments to guide thought and regulate its expression. The Jesuits acted on this theory, and resorted to repressive power and the secular arm whenever they could. The Jansenists repudiated the principle, but eagerly practised it whenever the turn of intrigue gave them the chance.