28 MAN THE ANIMAL 



bounded by choice and not by jealousy. If circumstances call 

 for it, another group's territory may be occupied j but this occu- 

 pation is tolerated, and the groups may combine in face of the 

 common need. The herd is in itself a bulwark against the hunter 

 and predator." 



Finally it is to be noted that agriculture promotes the de- 

 velopment of sociality to a far greater extent than the more 

 primitive culture types. Its territorial fixation in itself tends to 

 hold together by community of interest larger groups than the 

 immediate biological family, first through progressively more 

 and more remote collateral relatives. At a later stage exogamy 

 brings the necessity for social relations with similar "foreign" 

 groups. 



As has already been pointed out the most momentous cul- 

 tural epoch in man's history began when he became aware that 

 he was able to get a living by a wide variety of techniques 

 different in kind from the three that have been discussed, and 

 embarked in a big way upon the industrial-commercial-servke 

 mode of life. It automatically and at once appeared to, and in 

 a comparative sense in fact did, achieve a degree of economic 

 security never before dreamed of. If a living could be got by 

 making or doing things for people, a job was plainly going to 

 be at hand so long as there were people about. The physical labor 

 necessary to get this security was again plainly on the whole 

 a mere fraction of that required under the old techniques. 

 Organ-adding helped to guarantee this. Territorial require- 

 ments became minimal. In fact the nature of the technique itself 

 demanded higher and ever higher densities of population per 

 unit of area, leading rapidly to the development of ever larger 

 and larger cities until the average density of population over the 

 whole land surface of the globe, including all the bad and un- 

 inhabitable land in the computation, has now come to be about 

 41 persons per square mile. The necessity for nomadism dis- 

 appeared, to be replaced by almost obligatory domesticity and 

 fixed habitation. Not merely was it conducive to social organi- 

 zation but it absolutely required and led to a most extraordinarily 



