I. 



The Evolution of Consciousness. 



I PROPOSE to set before the readers of Natural Science, in as 

 brief and simple a form as possible, an hypothesis concerning the 

 evolution of consciousness which appears to me to be the legiti- 

 mate outcome of enquiries which are strictly scientific. I use the 

 word consciousness in its broadest and most comprehensive sense, as 

 embracing all that belongs to feeling, sentience, or the psychical 

 aspect of existence. 



Let us take our stand at starting on the firm foundation of 

 common observation. I hold in my hand an object, not unfamiliar to 

 some naturalists, a briar-wood pipe. I touch it, see it, taste it, smell 

 it, and hear its pleasant gurgle as I draw the smoke into my mouth. 

 If anything in the world is real to me, that pipe is real. I shall take 

 it as my standard of real existence. Now in what does this real 

 existence consist ? I may state the answer to this question in two 

 forms, both of which are different expressions of the same fact : — 

 (i) An object in consciousness exists. (2) There is a conscious- 

 ness of the object. These are obviously only different ways of 

 putting the same fundamental fact of experience. But in the 

 first, prominence is given to the objective side of the fact, while in 

 the second prominence is given to its conscious or subjective side. 

 Physical science takes up the objective side for special study and 

 investigation. It explains the object-in-consciousness which is for 

 direct observation a pipe in terms of other objects-in-consciousness, 

 molecular vibrations, modes of energy, and so forth. It thus reaches 

 what Dr. Johnstone Stoney calls the diacrinominal hypothesis, that all 

 objective phenomena are constituted by motions or groups of motions; 

 or some other such physical explanation of the objective world. But 

 it never shakes itself free of consciousness. It explains this object- 

 in-consciousness in terms of other objects-in-consciousness. It can 

 do no more. 



Let us here digress for a moment, that we may clearly grasp what 

 is meant by the words " object " and " objective." They are used 

 in two closely-connected and yet somewhat different senses. In what 

 may be called the narrower sense, the word " objective " applies to all 

 that belongs to the primitive perceptual object-in-consciousness as 

 contrasted with that which belongs to the consciousness-of-the-object. 

 Thus all that we know, or can know, concerning my pipe, as regarded 

 by physical science, is objective knowledge, as contrasted with 

 all that we know, or can know, concerning my impression or idea 



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