Consciousness. 965 



them, constitutes our consciousness for that moment, and when a new 

 direction of the attention brings forward new sensations, the conscious- 

 ness becomes different. So it is not the same for any two minutes. A 

 great many different names have been given to various sorts of mental 

 action, such as perception, ideation, judgment, volition, &c. , and the 

 general term, thought, which covers all these and many more. It was 

 pointed out on page 760 that these mental processes can all be carried 

 on without arousing any consciousness that connects them with the 

 waking state, and that therefore, we should recognize these processes as 

 distinct from sensations. Thus we have sensory impressions which are 

 not sensations but which may give rise to sensations, and likewise we 

 have perceptions, volitions, and thoughts in general, which are not them- 

 selves sensations, but which may give rise to them. When a sensation 

 is experienced, whether it be of sight or sound, or of a purpose or a 

 thought, we are conscious of such sound or purpose or thought. It 

 matters not whether the sensation is got as the result of an impact of 

 energy from the external senses, or of one from the internal senses; the 

 physiology of it is just the same. The distinction between conscious 

 brain action and unconscious brain action has usually been ignored, so 

 that the terms used, being applied indiscriminately to one class or the 

 other, produce confusion. Sensibility, feeling, sensation, pleasure and 

 pain, knowledge, &c. , which are all sensations and depend upon a com- 

 mon form of energy, and are all covered by the general term conscious- 

 ness, have not been sufficiently distinguished from impression, percep- 

 tion, ideation, reason, and will, all covered by the term thought. Con- 

 sciousness and thought, used as thus defined, principally though per- 

 haps not exclusively constitute the mind. Consciousness and thought, 

 then, are different and distinct functions of the nervous tissues, although 

 the former, when it is in activity, is a sequel to the latter and is therefore 

 associated with it, so it is easy to recognize the thoughts that occur 

 during the activity of consciousness, while it is equally easy for those 

 not so associated to escape observation. 



It was pointed out in last chapter how sensibility may be inhibited in 

 a particular case without inhibiting the physiological process which pre- 

 cedes and normally gives rise to it. This shows the fact that the functions 

 are really two, and that though so intimately connected as antecedent 

 and consequent, the latter may be suppressed without the nullification of 

 the former. It is true that this appears to be the case in the uncon- 

 scious cerebration discussed in chapter 75, but it is supposed by some 

 writers that at the time the brain action takes place there is a conscious- 

 ness of it which lapses before it can be connected with the general con- 

 sciousness of ordinary life, so it is forgotten. While it may not be 

 easy to prove this view incorrect in particular cases, the facts in hyp- 



