INTRODUCTIONand the existence of conflict as factors that influence selectivity. He
cites Julian Ribera's theory of imitation, which explains the exchange
of cultural elements between two cultures that are in contact in terms
of communication, the presence or absence of cultural barriers to
communication, and the social and psychological receptivity of the
recipient culture.7 With certain modifications these explanations also
serve for continuity through transmission in the case of Iraq where
the conditions for successful transmission were the survival of the
former culture, contact with the newcomers, communication, and re-
inforcement.
Reinforcement refers to the way an apparent similarity of customs
or similar, common, or shared interests makes it easier for two pop-
ulations that are in contact to increase their resemblance to each other.
Where such reinforcement exists, there is a tendency for similarities
to increase. When reinforcement is absent, there is resistance to such
acculturation. Recurring evidence that something like this was hap-
pening in early Islamic Iraq made it necessary to consider reinforce-
ment as a factor in cultural interaction. A similar idea, usually called
receptivity, has been used in diffusion theory. Rosenthal suggests that
the parallel between Platonic political ideas and the Islamic concept
of Mul).ammad as an ideal ruler enabled Platonic ideas to enter Islamic
political theory.8 Gibb used a form of it to explain the selectivity of
Europeans in their borrowing from Islamic civilization. People on the
receiving end of transmission by diffusion tend to disregard those
things which conflict with their own values and accept or adopt only
those things which are perceived as serving their own needs.^9 Hodgson
repeated this idea in the form that receptivity is determined by par-
ticular needs and interests. iD Glick gives a fairly complete statement
of the importance of receptivity for transmission by diffusion:
... even if the agents of diffusion are abundantly present ... an
idea may not diffuse unless it is congruent with the dominant modes
of thought of the recipient culture. If incongruent (or apparently so)
it must be stated in familiar terminology or placed within a rec-7 T. Glick, Islamic and Christian Spain in the Early Middle Ages (Princeton, 1979),
pp. 7,285.
8 E.!.]. Rosenthal, Political Thought in Medieval Islam (London, 1958), pp. 57-58.
9 H.A.R. Gibb, "The Influence of Islamic Culture on Western Europe," Bulletin of
the John Rylands Library 38 (1955-56), 85-87.
10 Hodgson, Venture, I, 80.