Many groups besides the state sponsored religious rituals, and, as the Greeks well knew, such religious fragmentation had the potential to nourish conflict. The most elementary and persistent group within society is the family. Since at least the time of Aristotle the family has been seen as the foundation of human community; but as has likewise been noted since at least the time of Aeschylus, family allegiance is an ever-present danger to the solidarity of the larger political order. Moral and religious obligations to the family may conflict with duty to the state. In the Laws, Plato notoriously urged that family cults should be entirely subordinated to those of the state: ‘‘let nobody possess shrines in private houses; whenever anyone is disposed to sacrifice let him go to the public shrines’’ (Laws 909d-910e). Typically family religious rites were observed, for example, at childbirth and marriage, or in connection with farming. The most prominent and socially explosive religious duty of families, however, was their responsibility to the dead. Sophocles in his Antigone has left the most famous statement: there the eponymous character is faced with the dilemma of her duty to obey state decree and leave her traitorous brothers to lie dead on the field of battle as carrion for dogs and birds, or obey her familial duty and give them burial. The state attempted to regulate mourning; female lamentation was considered especially dangerous.
Some have attempted to make sense of the welter of Athenian religious groups by insisting on a basic distinction between obligatory and voluntary groups. Membership in certain organizations that practiced ritual, including tribes and demes, gene and phratries, and even the nuclear family, was obligatory for Athenians: by the classical period membership was inherited: ‘‘opting out’’ of civic religion amounted to ‘‘opting out’’ of the state and family - a patent impossibility. It was possible, however, to join (or to refuse to join) other cultic organizations; as a consequence it has sometimes been argued that such groups satisfied a spiritual need unrequited by civic religion. Most notable among such associations are thiasoi and orgeones. The word thiasos refers originally to a Dionysiac association. The group name orgeones derives from the word for cultic ritual, orgia. These groups, though best attested in the hellenistic period, certainly existed from at least the sixth century, and probably earlier. In the classical period it is difficult to discern the nature of the constituency of such groups; in the hellenistic period they show great variety in their composition: some included citizens, others women, metics, craftsmen, even slaves; some had mixed memberships. Some approximated to trade unions, others to burial clubs.