THE OEIGIN OF TEADITION 421 



skill. For this destructive element is a kind of negative fertility, 

 and just as fertility is on the whole favourable to progress in skill, 

 so what is equivalent to its absence is a hindrance to progress in 

 skill. 



3. Fertility is thus relative to the tradition prevalent at any 

 one time. Let us suppose that man has spread over the surface 

 of the world and that the tradition present is everywhere very 

 similar, being of a simple form so far as skill is concerned, and 

 consisting in a rudimentary knowledge of hunting and fishing. 

 It is clear that certain areas — the great deserts, the frozen wastes 

 of the north — will be absolutely infertile ; with this degree of 

 skill only, life cannot be maintained there. The remaining areas 

 will vary from those which are just sufficiently fertile to permit 

 of life being maintained to those which are the most fertile relative 

 to this particular degree of skill. Supposing for the moment that 

 the degree of skill remains everywhere similar, it follows, from 

 what has been said earlier, that population will be most dense 

 and the return per head highest where the fertihty is greatest. 

 Other things being equal, differences in fertility are thus responsible 

 for important differences in social life. 



From these differences in fertility therefore consequences of the 

 greatest importance follow. In the first place, where population 

 is most dense, there, other things being equal, will be the greatest 

 amount of contact between men. With the results that flow 

 from contact we shall deal later, but it may be mentioned here 

 that contact is in itself a stimulus leading to the origin of, additions 

 to, and modifications of, tradition, and that the greater the amount 

 of contact the more quickly and the more thoroughly is tradition 

 transmitted. Therefore, in the first place, where the fertility is 

 greatest, there will be the greatest opportunity for existing 

 tradition to be quickly absorbed. In the second place, quite 

 apart from the question of contact, where fertility is greatest 

 there is also for other reasons the greatest stimulus to increase in 

 skill. To illustrate this point let us remember in what fertility 

 consists. The existence of areas of greater fertility implies that 

 there are in such areas either a greater abundance of animals, 

 plants, minerals, and so on which can be of use, or a greater 

 variety, or both together. Let us further remember how inventions 

 come about. For thousands of years in a variety of ways the fact 

 that the seed if sown would produce its like in twenty-, fifty-, or 



