Il8 THE FOUNDATIONS OF ZOOLOGY 



is universal, but since the welfare of the species is usually iden- 

 tical with that of the constituent individuals it is not obvious 

 unless the good of the species demands the sacrifice of individuals. 



Long journeys are hazardous. Every California salmon which 

 enters upon the long journey to the breeding ground is destroyed, 

 and the whole race is wiped out of existence for the good of 

 generations yet unborn. Very few shad ever return to the ocean, 

 and storm and accident and ruthless enemies work their will on 

 the migrating birds and decimate them without mercy, yet the 

 dangerous return to safe breeding grounds still goes on in order 

 that children which are yet unborn may survive to produce chil- 

 dren in their turn. 



The safeguards which nature throws around eggs, and infants, 

 and immature animals, and the indifference to the fate of the 

 mature animals which seems to be exhibited by the influences 

 which have shaped species into fitness for their environment, are 

 facts which must never be lost sight of; for if we forget them, 

 our attempts to understand the history of the properties of living 

 things or the meaning of our own nature are certain to mislead. 



Transition from the migration of the salmon to the altruistic 

 moral sense of ethical man may seem abrupt, yet the two subjects 

 may not be so far apart as they seem, if the natural attributes 

 of every living thing are primarily for the good of others, as I 

 have sought to show in the last two lectures. 



The fish owes its existence to the migratory impulse, which is 

 therefore useful, although it is not useful to the fish that migrates. 

 It has a utilitarian basis and a utilitarian history ; but if the salmon 

 were enlightened, its actions would exhibit enlightened self-sacri- 

 fice and not enlightened selfishness. 



Many good and thoughtful people hold that proof that our 

 moral sense has had a natural history would have very dreadful 

 consequences ; that it would show that duty is not duty, right 

 and wrong neither right nor wrong, and that the significance 

 man has attributed to this part of his nature a mistake. 



I cannot believe anything so beneficial and wholesome as the 

 increase of natural knowledge can lead to disaster, and while 

 I do not suppose my own inability to see why these dreadful 

 consequences should follow will count for much, this inability is 



