Not before the legal customs of all the peoples of the earth have been collected will ethnological jurisprudence be in a position to furnish a successful solution of the task it has set itself,—the task namely of a causal analysis of all the phenomena of the jural life of the human race. Yet to a certain extent this task may be undertaken at present, even with a relatively limited store of material. The starting-point for the ethno-juristic investigation of the phenomena of jural life is furnished by the ethno-juristic parallels, legal customs that are found uniformly appearing among the nations, without there being any reason to assume that one nation has received them from another. Legal customs of this character are in part so universally diffused over the earth that they may be characterised as a common possession of mankind; in part they appear sporadically among unrelated peoples; in part they are restricted to more limited domains. The most important legal customs are those that have universal dissemination; for here it may be assumed that they are a necessary emanation of the social side of human life. Legal customs that occur only sporadically, but appear uniformly among unrelated peoples, must likewise be regarded as the products of the universal nature of man, yet only as such that _can_ arise under definite conditions of existence. Legal customs that occur only in limited ethnological domains will have to be referred to the peculiar character of definite peoples and tribes. Legal institutions of universal character are, for example, the forms of marriage by capture and purchase of the bride, blood-vengeance, the right of refuge, the systems of composition, ordeals, oaths, and so forth. Almost universal are the levirate, and the betrothal of children. Sporadically among unrelated peoples appear: the seizure of the corpse of the debtor for debt; execution by fasting, whereby the creditor brings pressure to bear upon his debtor by having him fast a definite period of time before his dwelling; the custom of the chief doing combat with his grown up son, to whom the command of the tribe passes if he conquers his father; and so forth.[6] Frequently it is the most curious customs that thus recur, among peoples that are completely separated from each other by oceans and inaccessible mountain ranges and have unquestionably never been in communication with each other.