Hugo Grotius

Dutch jurist, diplomat and natural-law philosopher (1583 to 1645). In De Jure Belli ac Pacis (1625) he grounded a body of natural law in reason and in humanity's inherent sociability rather than in scripture or divine command, arguing in his famous etiamsi daremus formulation that this law would bind even if one were to concede, contrary to fact, that God did not exist. That secularizing move, natural law as a rational structure discoverable independent of revealed religion, places Grotius squarely in the natural-law tradition running from Aquinas's theological version through Grotius's own rationalist reworking to Pufendorf and Locke, and it is this move, more than any single doctrine, that later historians credit with opening natural-law reasoning to thinkers who did not share a common theology. His earlier Mare Liberum (1609) applied the same natural-law reasoning to argue for freedom of navigation on the open seas.