140 ORGANIC EVOLUTION — MENTAL 



as factors of survival, yet even in the highest animals, 

 e. g. in man, for whom the environment is most complex 

 and heterogeneous, both are present as essential factors 

 of survival. In them reflex action by means of par- 

 ticular reactions still provides against particular and 

 generally oft-recurring events, of such a kind as, if not 

 provided against, would result in the destruction of the 

 organism or of the species. As examples of such reflex 

 actions present in man may be quoted, the movements 

 of various hollow viscera, the acts of breathing, swallow- 

 ing, and coughing, and in infants, that of sucking. 

 Instinct is represented by various emotions, the existence 

 of which is necessary for the preservation of the indi- 

 vidual, or of the race, e. g. sexual and parental love, 

 love of life, jealousy, rage, fear, hate, &c.^ Generally 

 speaking, reflex action and instinct provide reactions 

 against such events as invariably happen to every indi- 

 vidual, and are . of such a nature as, if not provided 

 against by unfailing machinery, would lead to destruction 

 of the individual, or at any rate to cessation of the race ; 

 and this machinery, as I have said, is obviously inborn 

 and transmissible. 



But reason is obviously neither inborn nor transmis- 

 sible. It is obviously acquired anew by every individual, 

 only the power of acquiring it being inheritable ; and 

 the extent to which it is acquired in each organism 

 depends (1) on the organism's power of varying, of 



^ Sexual and parental love, fear, and love of life are clearly 

 necessary for the preservation of tlie race or of the individual, on 

 whose preservation depends that of the race. As regards hate, 

 that individual who has not the instinct is less likely to survive 

 and have offspring than the individual who, having it, seeks to 

 injure or destroy those that seek to injure and destroy him ; so 

 also with the instinct of rage ; as regards jealousy, an individual, 

 who views with indifference the advances made to his mate or 

 mates by individuals of his own sex, is likely to have a smaller 

 share in continuing the race than an individual who resents such 

 advances. 



