Hugo Grotius, “Prolegomena” to the The Law Of War And Peace” (1625)
Source
Author: Hugo Grotius (1583-1645)
The Classics of International Law. Edited by James Brown Scott, President of the Institute of International Law, President of the American Institute of International Law. De jure belli ac pacis libri tres, by Hugo Grotius. (Oxford: At the Clarendon Press, 1925). "Prolegomena", pp. 9-30.