THE NATURE OF CONTINUITYtion. The members of such communities tend to be stratified internally
according to relative differences in wealth and power.
There seem to be three main modes of social organization or dif-
ferentiation in such a society: stratification, religious communal iden-
tities, and kinship. All three are equally real. Although they normally
govern different aspects of life they sometimes conflict or overlap. As
an historical social process, kinship, at least at the tribal or clan level,
tends to be replaced or minimized by other associative bonds in this
kind of society. This may be assisted by forms of substitute kinship
and by providing the social ethics of kinship with a religious sanction.
It is also possible for religious and tribal leaders to emphasize religious
and tribal identities in their own interest, which serves to divert at-
tention from socioeconomic identities, interests, and stratification. In
addition, it is· worth suggesting that ethnic and religious categories
provide relatively stable alternatives for personal identity in an eco-
nomically fluid society compared to identities based on socioeconomic
stratification which are apt to change due to socioeconomic mobility.
Finally some comments concerning the social nature of historical
continuity and change are in order. Cultural continuity, diffusion, and
change are intimately connected to the survival and migration of peo-
ple, to their location in relation to people of different cultures, and to
the degree of sociocultural density and intermingling. Cultural density
contributes to linear continuity, increases stability, and minimizes change.
Cultural intermingling in the form of ethnic, linguistic, and religious
pluralism provides greater opportunity for syncretism, interpenetra-
tion, and mutual influences by different kinds of people on one another.
Continuity through transmission should not be represented as a static
borrowing or adoption by people of one culture from those of another,
but should be understood in terms of creative adaptation and contin-
uing development. When transmission (or diffusion) is assisted by
reinforcement, the reasons for the existence of reinforcement should
be sought. It is accidental? Is it to be explained by some universal
quality such as human nature? Is it a matter of similar development,
backgound, or common interests? In the case of Iraq, the evidence
points to extensive contact between Sasanian territories and Arabia
during the sixth century. It is a mistake to think of Arabia as being
culturally isolated or as being only on the receiving end of cultural
diffusion. Parts of eastern and southern Arabia were under direct or
indirect Sasanian rule and economic ties were increasing. The con-
quests of Khusraw Parviz in the early seventh century are symptomatic