164 SECTIONAL ADDRESSES. 
culture is “ primitive’ in the sense that it represents the early beginnings 
of human society. On the contrary, Australian culture is a highly 
specialised one, in which there has been an extreme elaboration of the 
kinship organisation, and it is exactly for this reason that I would select 
it for the study of any problems relating to kinship. Australia represents 
not the beginning but the end of a long line of development of kinship 
structure. Thus, my reasons for selecting Australia are the exact 
opposite of those put forward by earlier writers who have made the same 
selection. 
Having selected a first field for comparative study I would compare 
the social organisation, as a whole, of all the Australian tribes about which 
we have adequate information, in order to define what is the nature of the 
correlation between the rules prohibiting marriage and the social structure. 
In other words I should be seeking to define as precisely as possible the 
function of such rules as part of the total system of social integration. 
The investigation has to rest on the detailed examination of variations. 
As the result of such a study of Australia we can reach a number of 
significant generalisations. We shall, for example, reach certain pro- 
visional conclusions as to the nature (not the origin) of exogamy. These 
conclusions must now be tested by a similar study of other types of culture. 
It would be impossible for one student even in a lifetime to make a 
thorough investigation of all known cultures in this way. That is why 
the co-operation of a number of students in the study of any single problem 
is so essential in sociology. But a close study of one other type of culture 
sufficiently different from the Australian would permit of a very valuable 
verification of the provisional results obtained. 
When a theory as to the nature and function of the prohibition of 
incest has thus been reached, the next step will be to seek for the experi- 
mentum crucis by which it can be more critically tested. Such a crucial 
instance will often be one which appears to conflict directly with the theory. 
Thus, on my own theory we ought to find marriage everywhere prohibited 
between parent and child and between brother and sister. The various 
societies in which the marriage of brother and sister is permitted, therefore, 
offer us an opportunity of testing the theory, for we must be able to explain 
these exceptions on the basis of the theory itself. The exception must 
prove the rule. Other similar crucial instances can be sought by which 
to test the validity of the general theory. 
As a result of such an investigation we should, if we are at all successful, 
reach certain conclusions as to the relation between moral obligations and 
social structure. In other words, we should have learnt something about 
the place of such obligations in social integration. Sociology would then 
have to undertake similar investigations on other problems within the 
general problem. We might study in the same way the obligations 
relating to the taking of human life, or those relating to the rights of 
property. As the final result of such a series of related studies we could 
arrive at a theory of the nature and function of morality in general. 
Incidentally, of course, any single investigation of this kind must be linked 
with and throw light on a great number of other sociological problems. 
Thus, the study of the prohibition of incest necessarily involves a close 
study of kinship from other aspects also. 
