WILL. 683 



tic, and then keep their limbs outstretched for a length of 

 time quite unattainable by the waking will. M. Janet 

 thinks that in all these cases the outlying ideational 

 processes in the brain are temporarily thrown out of 

 gear. The kinsesthetic sensation of the raised arm, for 

 example, is produced in the patient when the operator 

 raises the arm, this sensation discharges into the motor cell, 

 which through the muscle reproduces the sensation, etc., 

 the currents running in this closed circle until they grow 

 so weak, by exhaustion of the parts, that the member slow- 

 1}^ drops. We may call this circle from the muscle to K, 

 from K to M, and from M to the muscle again, the ' motor 

 circle.' We sJioidd all be cataleptics and never stop a mus- 

 cular contraction once begun, ivere it not that otlier processes 

 simultaneously going on inhibit the contraction. Inhibition is 

 therefore not an occasional accident; it is an essential and unre- 

 mitting element of our cerebral life. It is interesting to note 

 that Dr. Mercier, by a different path of reasoning, is also 

 led to conclude that we owe to outside inhibitions exclu- 

 sively our power to arrest a movement once begun.* 



One great inhibiter of the discharge of K into M seems 

 to be the painful or otherwise displeasing quality of the 

 sensation itself of K ; and conversely, when this sensation 

 is distinctly pleasant, that fact tends to further K's dis- 

 charge into M, and to l.eep the primordial motor circle 

 agoing. Tremendous as tlie part is which ])leasure and 

 pain play in our psychic life, we must confess that absohite- 

 ly nothing is known of their cerebral conditions. It is hard 

 to imagine them as having special centres ; it is harder still 

 to invent peculiar forms of process in each and every centre, 

 to which these feelings may be due. And let one try as 

 one will to represent the cerebral activity in exclusively 

 mechanical terms, I, for one, find it quite impossible to 

 enumerate what seem to be the facts and yet to make no 

 mention of the psychic side which they possess. However 

 it be with other drainage currents and discharges, the drain- 

 age currents and discharges of the brain are not purely 

 physical facts. They are psycho-physical facts, and the 



* The Nervous System and the Mind (1888), pp. 75-6. 



