THE FUNCTION OF CONSCIOUSNESS. 509 



ternative true? There seems to be no escape from it, 

 and it accords also with our personal human experi- 

 ence of the agency of conscious states in our various 

 activities, physical and mental. 



2. THE EFFECTS OF CONSCIOUSNESS. 



From the facts cited it is evident that sensation 

 (consciousness) has preceded in time and in history, 

 the evolution of the greater part of plants and animals, 

 both unicellular and multicellular. It appears also 

 that if kinetogenesis be true, consciousness has been 

 essential to a rising scale of organic evolution. 



Animals who do not perform simple acts of self- 

 preservation must necessarily perish sooner or later. 

 In fact it is impossible to understand how the lowest 

 forms of lifej utterly dependent as they are on physi- 

 cal conditions of many kinds, should not have been 

 all destroyed, were they not possessed of some degree 

 of consciousness under stimuli at least. And the case 

 is even plainer with the higher forms. We have only 

 to picture to ourselves the condition of a vertebrate 

 without general or special sensation, to perceive how 

 essential consciousness is to its existence. If now, as 

 maintained in Chapter IV., use has modified struc- 

 ture, and so, in cooperation with the environment, has 

 directed evolution, we can understand the origin and 

 development of useful organs. And we can under- 

 stand how by parasitism or other mode of gaining a 

 livelihood without exertion, the adoption of new and 

 skilful movements would become unnecessary, and 

 consciousness itself would be seldom aroused. Con- 

 tiued repose would be followed by subconsciousness, 

 and later by unconsciousness. Such appears to be the 

 history of degeneracy everywhere, and such is, per- 



