THE PROBABLE FUTURE OF THE HUMAN RACE. 147 



the people, and of decadence. Is not this what generally happens whea 

 there is a struggle between different influences ? Fixed, certain causes 

 increase or diminish slowly. We find to-day that many animal species 

 have become extinct. They at first became rare. Often driven from 

 their habitations, from place to place, they were at last reduced to a 

 single district, where some cause, perhaps a very unimportant one, 

 ended their existence. In former times, if we can judge sufficiently 

 from geological data, the living species have had a period of abundance 

 and extension followed by one of rarity and limitation. The human 

 species will describe in the same way a sort of curve, the extremes of 

 which escape our powers of observation, while the mean part power- 

 fully excites our attention. We know that one of these extremes has 

 already existed ; we foresee the time when man will occupy all the habita- 

 ble surface of the earth, and will have consumed that which is now found 

 accumulated by a long series of geological events. Without muck 

 imagination, we can then foresee the other part of the curve, tending to 

 some final point in the far future. Such are the probabilities according 

 to the existing state of things ; but the longer the time considered, the 

 more it is necessary to admit the possibility of events unknown, un- 

 foreseen, impossible even to be foreseen, which may introduce entirely 

 different conditions. 



In these suppositions or reflections I am at variance with Messrs. 

 Spencer and Galton in their writings upon this subject. Mr. Spencer* 

 speaks very little of the physical conditions to which man will be sub- 

 ject. He mentions only the alternation of ice at the two poles as neces- 

 sarily in time displacing man. Notwithstanding the calculations and 

 the hypothesis of Mr. Croll, this is perhaps the least certain and the 

 least important of the material modifications which the human species 

 will encounter. The increasing rarity of coal and the metals is muck 

 more evident, much nearer at hand, especially the nirity of such depos- 

 its of coal as are easily attained. As to the modifications of man him- 

 self, produced through variability, competition, and the selection whick 

 results, Mr. Spencer analyzes the question with skill, but, in my opinion, 

 not completely. The struggle, he says, becomes from century to century 

 more active on account of the increase of the population, and the prog- 

 ress of science, industry, and commerce, which compels individuals to 

 seek more knowledge and to exert greater effort. There will be, on thia 

 account, probably a more and more marked development of the intel- 

 lectual faculties, (vol. ii, pp. 496, 499,) and also those of morality, (p. 497.) 

 From these new intellectual and moral conditions, he says, there will 

 result a less degree of fecundity, which will become another source of 

 moral and intellectual progress. 



Mr. Galton t reasons very nearly the same as Mr. Spencer in what 

 concerns the probable intellectual development ; only he fears that the 



* Herbert Spencer's Principles of Biology, vol. ii, book G, ch. 13. 

 t Galton, Hereditary Genius, pp. 336-362. 



