The great general idea, the fundamental idea, underlying every persistent ancestor-worship, is that the welfare of the living depends upon the welfare of the dead. Under the influence of this idea, and of the cult based upon it, were developed the early organization of the family, the laws regarding property and succession, the whole structure, in short, of ancient society, - whether in the Western or the Eastern world.
But before considering how the social structure in old Japan was shaped by the ancestral cult, let me again remind the reader that there were at first no other gods than the dead. Even when Japanese ancestor-worship evolved a mythology, its gods were only transfigured ghosts, - and this is the history of all mythology. The ideas of heaven and hell did not exist among the primitive Japanese, nor any notion of metempsychosis. The Buddhist doctrine of rebirth - a late borrowing - was totally inconsistent with the archaic Japanese beliefs, and required an elaborate metaphysical system to support it. But we may suppose the early ideas of the Japanese about the dead to have been much like those of the Greeks of the pre-Homeric era. There was an underground world to which spirits descended; but they were supposed to haunt by preference their own graves, or their "ghost-houses." Only by slow degrees did the notion of their power of ubiquity become evolved. But even then they were thought to be particularly attached to their tombs, shrines, and homesteads. Hirata wrote, in the early part of the nineteenth century: "The spirits of the dead continue to exist in the unseen world which is everywhere about us; and they all become gods of varying character and degrees of influence. Some reside in temples built in their honour; others hover near their tombs; and they continue to render service to their prince, parents, wives, and children, as when in the body." Evidently "the unseen world" was thought to be in some sort a duplicate of the visible world, and dependent upon the help of the living for its prosperity. The dead and the living were mutually dependent. The all-important necessity for the ghost was sacrificial worship; the all-important necessity for the man was to provide for the future cult of his own spirit; and to die without assurance of a cult was the supreme calamity .... Remembering these facts we can understand better the organization of the patriarchal family, - shaped to maintain and to provide for the cult of its dead, any neglect of which cult was believed to involve misfortune.
The reader is doubtless aware that in the old Aryan family the bond of union was not the bond of affection, but a bond of religion, to which natural affection was altogether subordinate. This condition characterizes the patriarchal family wherever ancestor-worship exists. Now the Japanese family, like the ancient Greek or Roman family, was a religious society in the strictest sense of the term; and a religious society it yet remains. Its organization was primarily shaped in accordance with the requirements of ancestor-worship; its later imported doctrines of filial piety had been already developed in China to meet the needs of an older and similar religion. We might expect to find in the structure, the laws, and the customs of the Japanese family many points of likeness to the structure and the traditional laws of the old Aryan household, - because the law of sociological evolution admits of only minor exceptions. And many such points of likeness are obvious. The materials for a serious comparative study have not yet been collected: very much remains to be learned regarding the past history of the Japanese family. But, along certain general lines, the resemblances between domestic institutions in ancient Europe and domestic institutions in the Far East can be clearly established.
Alike in the early European and in the old Japanese civilization it was believed that the prosperity of the family depended upon the exact fulfilment of the duties of the ancestral cult; and, to a considerable degree, this belief rules the life of the Japanese family to-day. It is still thought that the good fortune of the household depends on the observance of its cult, and that the greatest possible calamity is to die without leaving a male heir to perform the rites and to make the offerings. The paramount duty of filial piety among the early Greeks and Romans was to provide for the perpetuation of the family cult; and celibacy was therefore generally forbidden, - the obligation to marry being enforced by opinion where not enforced by legislation. Among the free classes of Old Japan, marriage was also, as a general rule, obligatory in the case of a male heir: otherwise, where celibacy was not condemned by law, it was condemned by custom. To die without offspring was, in the case of a younger son, chiefly a personal misfortune; to die without leaving a male heir, in the case of an elder son and successor, was a crime against the ancestors, - the cult being thereby threatened with extinction. No excuse existed for remaining childless: the family law in Japan, precisely as in ancient Europe, having amply provided against such a contingency. In case that a wife proved barren, she might be divorced. In case that there were reasons for not divorcing her, a concubine might be taken for the purpose of obtaining an heir. Furthermore, every family representative was privileged to adopt an heir. An unworthy son, again, might be disinherited, and another young man adopted in his place. Finally, in case that a man had daughters but no son, the succession and the continuance of the cult could be assured by adopting a husband for the eldest daughter.