Reply to Mr Wallace's Theory of Birds' Nests 139 



own. Others, such as " derivation," the " homologies," &c., 

 are regarded as less original, because first suggested by older 

 authors; but, putting aside the abstract reflection, that there is no 

 such thing as originality (everything that enters the mind of man 

 being suggested by something else), we have always considered 

 that in this estimate an injustice is done to Mr Darwin. According 

 to our conception science owes vastly more to him for the way in 

 which he has established the principle of derivation on a firm basis 

 than for his other speculations, which have not brought the same 

 conviction to our mind. Our objections to the latter may be 

 briefly indicated in a few words — we have not space for more than 

 an indication. 



Mr Darwin regards the struggle for life as a means by which the 

 less perfect conceptions of nature, which he assumes to be con- 

 stantly appearing, are wiped off ; it is as a destructive agent that 

 he chiefly regards it. We regard it from the opposite point of 

 view — as a preservative rather than a destructive agent — as a means 

 of strengthening and maintaining the life of species^ in the same way 

 that pain maintains and restores the life of individuals. Without 

 the blessing of pain we should succumb to every accident and 

 ailment — without sorrow, happiness would be impossible — without 

 grief there could be no joy. In the same way, but for the struggle 

 for life, general degeneracy would be the result, and the species 

 would come to an end from the degradation of its constituent parts. 



Next, as to the slow and gradual change which Mr Darwin 

 maintains to be in constant operation in all organic beings, we 

 maintain that if such a change really were constantly in progress 

 without intermission, the inevitable result must have been the con- 

 fusion of all species. It could not be otherwise. No mathematical 

 problem can be more inexorable. If there were no pause or 

 resting-place in the course of change there could be no distinction 

 of species — the whole of organic life would be one confused mass 

 of individuals. To mark off that mass into sections, there must 

 be some pause in the process of change. We have elsewhere 

 ("Geographical Distribution of Mammals") argued that the real 

 explanation of what we see is, that organic life is endowed with a 

 plasticity and readiness to change whch only requires stimulus to 

 force it into operation, and that the usual stimulus is change of 

 conditions of life ; without change of condition the species rests 

 undisturbed ; with it, it produces new forms. This would explain 

 both the continued endurance of species and the appearance of 



