THE UTILITY OF HUMAN CHARACTERS 219 



unused hitherto are extremely rich and suggestive, and will furnish, 

 not only materials from which may be drawn some conclusions, 

 which to me seem indisputable, but also the means of testing the 

 thinking by which they are reached. We shall be embarrassed, 

 however, by the mass of error which has collected around the 

 subject. In all ages the thoughts of men have been concentrated 

 on themselves, their parents, children, and fellows, and traditions 

 have arisen which, though far from the truth, are yet owing to a 

 human mental characteristic of the highest general utility l very 

 hard to break down. 



359. The reader must bear in mind certain conclusions which 

 we have already reached. Like other living beings, man is mani- 

 festly a bundle of adaptations. Indeed, since he is better known, 

 he is more manifestly a bundle of adaptations than any other 

 type. Beyond doubt some human characters have no utility. 

 Of these a few may be by-products of evolution correlated to more 

 useful traits, the only one of the kind of any importance known 

 to me being susceptibility to the charm of alcohol and other 

 narcotics. Others, such as the colour of blood and bone, are 

 chance qualities of useful characters chance in the sense that in 

 all probability they have not arisen through selection. These, 

 however, do not enter into the account ; of necessity blood and 

 bone must have some colour. 2 Yet others have lost their utility, 

 and have become or are becoming vestigial. Speaking generally, 

 in only a few instances has the past or present utility of a character 

 not been ascertained. There can be no doubt, therefore, that the 

 immense majority of human characters, whether in the trunk, 

 limbs, or head, are adaptations. The growth of modern physio- 

 logy implies merely an increased power of interpreting human traits 

 in terms of their utilities. 



360. We also reached the conclusion that all adaptation has 

 resulted from the combined action of progression and retrogression, 

 the former being a product of selection, the latter usually following 

 cessation of selection. Given progression as an accompaniment 

 of selection, and retrogression as a correlate of cessation of selec- 

 tion, close adaptation is obviously inevitable. We concluded, 

 further, that this theory of evolution has for its necessary corollary 

 a theory of heredity which supposes (i) that the great mass of 

 variations are spontaneous, and, therefore, (2) that the germ-plasm, 

 so far as its hereditary tendencies are concerned, is highly in- 

 susceptible to the direct action of the environment ; (3) that 



1 See 663. See 649. 



