2l6 FROM FISH TO PHILOSOPHER 



to tie one moment to the next and to afford a basis 

 for anticipating the future— all neuromuscular reactions 

 would be essentially instantaneous and of Hmited value 

 for survival of the organism. Whether the time-binding 

 activity extends over a period of seconds or of years is 

 immaterial to the cogency of the definition. 



The evolution of the vertebrates thus leads us to an 

 unavoidable conclusion: consciousness is not unique to 

 man, to the primates, or to the mammals; it goes back 

 to the roots of vertebrate history and has been progres- 

 sively elaborated in content, coloring, and complexity 

 roughly in proportion to the evolution of the neuromus- 

 cular system. It cannot even be argued that conscious- 

 ness is a imique vertebrate invention— the crab, the octo- 

 pus, the butterfly, the ant, the bee all possess sensory 

 devices imparting to them the awareness of the world, 

 and all demonstrably engage in integrated, time-binding, 

 self-serving action; and it must be presumed that all par- 

 ticipate in some proportional measure in conscious ap- 

 preciation of themselves and their environment. 



But accepting this definition, it can tentatively be ar- 

 gued that the capacity for consciousness requires the 

 anatomical substratum of a nervous system of some sort, 

 with appropriate sensory, integrative, and motor com- 

 ponents, and one need not look for consciousness or any 

 similacrum thereof in lower forms of life such as the 

 Protozoa even though they swim or crawl and show 

 simple avoidance reactions, until it is demonstrated that 

 they show some capacity for time-binding and the in- 

 tegration of diverse stimuh— which, by present evidences, 

 they do not. 



On the other hand, it must not be supposed that be- 

 cause the mechanisms for integrated behavior are pres- 

 ent, the animal is necessarily a conscious creature. On 

 the contrary, as is well demonstrated in man, conscious- 

 ness requires a special type of neural activity. It can be 

 turned on and off, and this fact alone leads us to suspect 

 that sleep is a neural mechanism which has biological 



