Montesquieu

Montesquieu left two great legacies to the world: He formulated the theory of the British constitution which held the field for a century, and was the foundation of every constitutional government established during that period; and he gave a new direction to the study of legal and political science. He was one of the greatest of the apostles of liberty in modern times. Socially and politically, he belongs to the old régime, to the régime which in France passed away in 1789, which in England, where changes are less catastrophic, began to pass away in 1832. Scientifically also he belongs to a bygone age. His new ideas, his new methods, once so fresh, so attractive, so stimulating, have passed into and been merged in the common heritage of Western thought. But in his generation he succeeded, with a success beyond his most sanguine hopes, in doing what he tried to do - he made men think."