362 THE GRAMMAR OF SCIENCE 



development. It is this struggle which is the fundamental 

 formula for the description of all existing systems of 

 ownership and of marriage in its widest sense. In owner- 

 ship and marriage are further rooted the laws and institu- 

 tions even of our modern competing states. Sexual 

 instinct and the struggle for food have both separated 

 and combined individual men ; in them we find the basis 

 of both the egoistic and the altruistic instincts, of both 

 individualism and socialism in the more fundamental senses 

 of these terms. 



Systems of ownership and marriage have indeed been 

 modified by climate and geographical surroundings, but, 

 speaking generally, they have passed through much the 

 same development, it may be at very different periods, in 

 all quarters of the world. Fragments of the primitive 

 history of one society can often be linked together by our 

 knowledge of another society still existing in a backward 

 stage of civilisation. The like sequences in the stages of 

 social growth exhibited by most primitive societies un- 

 doubtedly arise from similarity in their general physical 

 environment and from the sameness of the characteristic 

 physiological instincts in man, which everywhere centre 

 in the satisfaction of hunger and in the gratification of 

 the sexual appetite. Diverse as at first sight ownership 

 and marriage may seem, they will yet be found on nearer 

 investigation to be closely associated. Broadly speaking, 

 each particular mode of ownership has been accompanied 

 by a particular form of marriage. These two social insti- 

 tutions have acted and reacted upon each other and their 

 changes have been nearly simultaneous. Ownership, 

 inheritance, common rights, are essentially connected with 

 the structure of the family, and therefore with the nature 

 of the sexual tie. Thus it comes about that primitive 

 history must be based upon a scientific investigation 

 into the growth and relationship of the early forms of 

 ownership and of marriage. It is only by such an investi- 

 gation that we are able to show that the two great factors 

 of evolution, the struggle for food and the instinct of sex, 

 will suffice to resume the stages of social development. 



