一国际法作为一个完整的法律体系形成于近代欧洲,有关国际法的学说也是在彼时彼地产生的。综观西方国际法理论,有所谓自然法学派、实在法学派、社会连带法学派、规范法学派等诸多流派。这些学派都以当时风行的西方法哲学思想为理论基础,反映了不同国家及其在不同时期的利益和要求。譬如,自然法学派用自然法的观点来看待国际关系,认为国际法是自然法的一部分,或者是自然法对国家之间关系的适用,国际法的效力来自人类的良知、人类的理性以及人类法律意识等。这种观点的直接理论来源是英国人霍布斯的哲学学说。霍布斯把世界严格区分为自然和社会两种状态。他认为,自然状态是一种人们相互残杀的永久的战争状态,为了避免使人类在这种状态中被消灭,就需要有引导人们保全自我的理性戒 As a complete legal system, international law was formed in modern Europe. The doctrine of international law also came into being at that time. Looking at the theory of Western international law, there are so many schools of so-called natural law schools, real law schools, social associated law schools and normative law schools. These schools are based on the popular western philosophy of law theory as a basis for the study, reflecting the different countries and their interests and demands in different periods. For example, the natural law school viewed international relations from the perspective of the law of nature, believing that international law is part of the law of nature or the application of natural law to the relations between nations. The effectiveness of international law comes from human conscience, human reason, and human legal awareness Wait. The direct theoretical source of this view is the philosophical doctrine of the British Hobbes. Hobbes divided the world strictly into two states of nature and society. In his opinion, the state of nature is a permanent state of war by which people kill each other. To avoid leaving human beings in this state, there is a need to have a rational precept that leads people to preserve themselves