294 POPULAR SCIENCE MONTHLY. 



attention to it. This we call conscious inhibition. It plays a great 

 role in our lives; but it does not mean necessarily that inhibited im- 

 pressions may not survive in memory and at a later time determine the 

 action taken; in such cases the potential reaction is stored up. (2) 

 Consciousness may evoke a reaction from a remembered sensation and 

 combine it with sensations received at other times. In other words, 

 consciousness has a selective power, manifest both in choosing from 

 sensations received at the same time and in combining sensations re- 

 ceived at different times. It can make synchronous impressions 

 dyschronous in their effects, and dyschronous impressions synchronous. 

 But this somewhat formidable sentence merely paraphrases our original 

 description: The function of consciousness is to dislocate in time the 

 reactions from sensations. 



This disarrangement and constant rearrangement of the sensations, 

 or impressions from sensations, which we gather, so that their connec- 

 tions in time are altered seems to me the most fundamental and essen- 

 tial characteristic of consciousness which we know. It is not improb- 

 able that hereafter it will become possible to give a better characteri- 

 zation of consciousness. In that case the opinion just given may 

 become unsatisfactory, and have to yield to one based on greater knowl- 

 edge. The characteristic we are considering is certainly important, 

 and so far as the available evidence goes it belongs exclusively to con- 

 sciousness. Without it life would have no interest, for there would be 

 no possibility of experience, no possibility of education. 



Now, the more we have learned about animals, the better have we 

 appreciated the fact that in them only such structures and functions 

 are preserved as are useful, or have a teleological value. Formerly a 

 good many organs were called rudimentary or vestigial and supposed 

 to be useless survivals because they had no known function. But in 

 many cases the functions have since been discovered. Such, for 

 example, were the pineal gland, the pituitary body, the suprarenal 

 capsules and the Wolffian body of man, all of which are now recognized 

 to be functionally important structures. Useless structures are so rare 

 that one questions whether any exist at all, except on an almost insig- 

 nificant scale. It has accordingly become well-nigh impossible for 

 us to imagine consciousness to have been evolved, as it has been, unless 

 it had been bionomically useful. Let us therefore next consider the 

 value of consciousness from the standpoint of bionomics.* 



We must begin with a consideration of the nature of sensations and 

 the object of the reactions which they cause. In the simpler forms 

 of nervous action a force, usually but not necessarily external to the 



* A convenient term, recently gaining favor, for what might otherwise be 

 called the economics of the living organism. Bionomics seems preferable to 

 ecology, which some writers are adopting from the German. 



