… is from page 633 of Will & Ariel Durant’s 1961 volume, The Age of Reason Begins; the Durants are here describing the jurisprudence of Hugo Grotius:
Natural law, then, is that system of rights and duties which follows from the essential nature of man as a rational being living in society. Whatever is necessary for his existence and his participation in society is his natural right, it is something due to his nature. The behavior of states should observe these rights.
DBx: Pictured here is Hugo Grotius (1583-1645).