Leach, student of Malinowski and Firth; believed that there was no inconsistency between ‘‘functionalism’’ and‘‘structuralism’’. His ‘structuralism’-cum-‘functionalism’ consisted in seeing ‘relational systems’ as ‘transformations’ of one another, that certain devices stemming from or assimilable to his mathematical and engineering training such as binary arithmetic, information theory, computer coding, could be deployed for perceiving patterns in classificatory thought, myth and ritual, and in social processes. He saw the possibility of establishing ‘cross cultural transcriptions’ as the objective of his notion of the comparative method. He rejected the substantive, methodological, and theoretical sub-missions ; and combined some features of ‘functionalist’ empiricism and pragmatism with ‘structuralist’ rationalism and deductive formalism in his studies.
Leach published a short, popular introduction to Lévi-Strauss in 1970, and, in 1983, Structuralist Interpretations of Biblical Myth. Leach brought the formal models process of structural functionalism. He showed the creative role of the individual in transforming culture. Leach made a tremendously important point by taking a regional rather than a local perspective.
Leach in book Political Systems of Highland Burma focused on how individuals work to achieve power and how their actions can transform society. Leach’s assertion in Political Systems was that events and behaviour on the ground are ‘only seen as structured when they are ordered by means of verbal categories’. The three categories of ideal political order that the Kachin themselves used in their political discourses were gumlao and gumsa which were respectively ‘democratic egalitarian’, and ‘ranked-aristocratic’ in their connotations; the third, shan, pertained to the monarchical/feudal conceptual ordering of the neighbouring valley centred people. Leach argued that these different forms in fact represented phases in a very long-term fluctuation from egalitarianism to hiearchy and back. The Kachins participated in a regional system that included all three forms of organization. Leach showed how they coexist and interact, as forms and possibilities known to everyone, in the same region. He also showed how Kachins creatively use power struggles, for example, to convert gumlao into gumsa organization, and how they negotiate their own identities within the regional system.
Leach’s explication of the gap between ‘ideal categories’ and ‘actual behaviour’, ‘rule and practice’ focused on how individual Kachin actors driven by self-interested power motives instrumentally manipulated the ambiguous meanings and contested the application of those categories to their on the ground situation.
The overall process of structural change comes about through the manipulation of these alternatives as a means of social advancement. Every individual of a society, each in his own interest, endeavours to exploit the situation as he perceives it and in so doing the bcollectivity of individuals alters the structure of the society itself. Thus functionalism is dynamic and diachronic.
Leach’s monograph from Sri Lanka (Pul Eliya, a Village in Ceylon: A Study of Land Tenure and Kinship) is a classical ethnographic study of economic organization in peasant society.