Relations between the Physical and the Moral. 221 



the unconscious would have the same limits, and the same extent 

 as ordinary psychology. It would be necessary to show at least, 

 as we view the matter that most, if not all, of the operations 

 of the soul may be produced under a twofold form ; that there are 

 in us two parallel modes of activity, the one conscious, and the 

 other unconscious. This study would require a volume. For our 

 purpose it will suffice here to show by some positive facts what 

 this unconscious activity is, and in what degree it can explain the 

 correlation of the physical and the moral. 



Passing from the simple to the composite, from reflex action to 

 unconscious cerebration, we will address our study of the uncon- 

 scious to the nerve-centres in the following order, viz. spinal cord, 

 rachidian bulb, annular protuberance, cerebellum, cerebral hemi- 

 spheres. 



i. The spinal cord is regarded by physiologists under a two- 

 fold aspect : as a conducting cord it transmits sensations to the 

 brain, and brings back thence motor excitations ; as nerve-centre 

 it is the seat of reflex action. Simple reflex action, which we may 

 define to be a simple excitation followed by a simple contraction, 

 is the first act of automatism, or of unconsciousness, that presents 

 itself to us. Reflex action consists essentially in movement in 

 a part of the body, called forth by an excitation coming from that 

 part, and acting through the intermediary of some nerve-centre 

 other than the brain. Proschaska, who was the first to study these 

 movements, called them ' phenomena of reflection of sensitive im- 

 pressions in motor impressions.' 



If we examine here, from our own point of view, the reflex actions 

 whereof the spinal cord is the centre, we shall find that their 

 distinctive character is that they are automatic, unconscious, and, 

 what concerns us far more closely, co-ordinated. * In those purely 

 reflex reactions/ says Luys, * which, owing to their automatism, 

 possess that determined and necessary character which is peculiar to 

 the mechanical contrivances of human industry, everything betrays 

 a sort of predestined consensus between the centripetal impression 

 and the centrifugal action which it calls forth, so essential to them 

 is it to be regular and co-ordinate.' l A few facts will place this in 



1 R;chcrches sur le Systerne Nerveux, p. 280. 



