ABSTRACT
A system of kinship and marriage can be looked at as an arrangement which enables persons to live together and co-operate with one another in an orderly social life. For any particular system as it exists at a certain time we can make a study of how it works. To do this we have to consider how it links persons together by convergence of interest and sentiment and how it controls and limits those conflicts that are always possible as the result of divergence of sentiment or interest. In reference to any feature of a system we can ask how it contributes to the working of the system. This is what is meant by speaking of its social function. When we succeed in discovering the function of a particular custom, i.e. the part it plays in the working of the system to which it belongs, we reach an understanding or explanation of it which is different from and independent of any historical explanation of how it came into existence. This kind of understanding of a kinship system as a working system linking human beings together in an orderly arrangement of interactions, by which particular customs are seen as functioning parts of the social machinery, is what is aimed at in a synchronic analytic study. In such an analysis we are dealing with a system as it exists at a certain time, abstracting as far as possible from any changes that it may be undergoing. To understand a process of change we must make a diachronic study. But to do this we must first learn all that we possibly can about how the system functioned before the changes that we are investigating occurred. Only then can we learn something of their possible causes and see something of their actual or probable effects. It is only when changes are seen as changes in or of a functioning system that they can be understood.
