lo THE POPULAR SCIENCE MONTHLY. 



to be necessary with the cessation of the process, will disappear. 

 While the benefits achieved during the predatory period remain a per- 

 manent inheritance, the evils, social and individual, entailed by it will 

 decrease and slowly die out. 



Thus, then, contemplating social structures and actions from the 

 evolution point of view, we may j)reserve that calmness which is need- 

 ful for scientific interpretation of them, without losing our powers of 

 feeling moral rei^robation or approbation. 



To these preliminary remarks respecting the mental attitude to 

 be preserved by the student of political institutions, a few briefer 

 ones must be added respecting the subject-matters he has to deal 

 with. 



If societies were all of the same species, and differed only in 

 their stages of growth and structure, comparisons would disclose 

 clearly the course of evolution ; but unlikenesses of type among 

 them, here great and there small, obscure the results of such com- 

 parisons. 



Again, if each society grew and unfolded itself without the intru- 

 sion of additional factors, interpretation would be relatively easy ; but 

 the complicated processes of development are frequently recomplicated 

 by sudden changes in the sets of factors. Now the size of the social 

 aggregate is all at once increased or decreased by annexation or by 

 loss of territory ; and now the average character of its units is changed 

 by the coming in of another race as conquerors or as slaves ; while, as 

 a further incident of this change, new social relations are superposed 

 on the old. In many cases, the repeated overrunnings of societies by 

 one another, the minglings of peoples and institutions, the breakings 

 up and reaggregations, so destroy the continuity of normal changes 

 as to make it extremely difficult if not impossible to draw con- 

 clusions. 



Once more, change in the average mode of life j^ursued by a so- 

 ciety, now increasingly warlike and now increasingly industrial, initi- 

 ates metamorphoses : changed activities generate changes of structures. 

 Hence, there have to be distinguished those progressive rearrange- 

 ments which belong to the further development of one social type, 

 from those caused by the commencing development of another social 

 type. The lines of an organization adapted to a mode of activity that 

 has ceased, or has been long suspended, begin to fade, and are traversed 

 by the increasingly definite lines of an organization adapted to the 

 mode of activity which has i-eplaced it ; and error may result from 

 mistaking traits which belong to the one for those which belong to 

 the other. 



Hence we may infer that, out of the complex and confused evi- 

 dence, only the larger truths are likely to emerge with clearness. 

 While anticipating that certain general conclusions are to be positively 



