Abstract: This paper re-examines Mauss's discussion in his book Gift on Roman, Classic Hindu, and Germanic laws of "Gifts", in conjunction with his speech on the Category of the Person given in 1938, and concludes that Indo-European gifts were unique exchanges for the first and second classes, and that the principles of gift exchange were different.
For Romans, the Real Law about res mancipi and the way of its exchange defined in Jus civile were closely related to the nature of Romulus's authority that was all about bonds and restrains. It became the core of the spirit of Roman gifts. The Germanic law, like that of the North American Indians, was based on peace between warriors. The threat of violence provided a guarantee of peace, so the gift was often thought to be toxic among German people. As for Hindus, the description of Anusasana-parva in Mahabharata embodied the inherent defects of the Dharma of Kshatriyas. This made the donation to Brahmin indispensable as means to make up for the incompleteness of the Dharma of Kshatriyas as well as a manifestation of the integration of the law with Brahmin's property rights. In short, for the first and second classes of Indo-Europeans, the gift was the law, the same as vaygu'a in kula trade and copper objects in potlatch.
However, the third-class people as the majority in the West does not have a way of exchanging gifts in accordance with the moral requirements, and unless the spirit of Germanic law is inherited, modern society could eventually fall into an inexorable moral dilemma. Rather than focusing on serving industrial and commercial law, modern states should assume the obligation of reciprocity in gift exchanges. Through comparing Maine's research on Roman law with the study of Indo-European society, this paper hopes to demonstrate that Mauss had built upon Maine's thoughts and developed his theory of social contract that was based on the law of Indo-European society, a quite different proposal to the social contract theory based on nature law.

Key words: social contract, Roman law, Germanic law, Indian law, obligatio