360 THE BODY AT WOKK 



The lower we descend the scale, the more inevitable do an 

 animal's movements become ; but there can be no doubt but 

 that consciousness is of value to an animal, as to Man, in that 

 it gives to its individuality the capacity, within such limits as 

 Nature has selected, of resisting or modifying its ancestral 

 instincts when they are not absolutely appropriate to the 

 occasion. 



Sentience implies personality. " No system of philosophy 

 can extrude the ego." The difference between the performance 

 of the animal machine as a physiologist studies it, and its 

 behaviour when under the control of its own driver, is the 

 difference between reflex action and choice. The ego inter- 

 acts with physical forces. It does not come within the province 

 of the physiologist to explain the source of the force which 

 interferes with force. He finds no trace of it on either credit 

 or debit side when making up the body's accounts. He is 

 unable to enter, " Item, to the development of consciousness 

 ... so much." He can form no conception of this immaterial 

 manif estent which hovers over the infinitely numerous serisori- 

 motor exchanges which are always occurring in the cortex of 

 the brain, giving to a particular group of agitations, now here, 

 now there, a special quality ; but the manifestent is needed to 

 account for the potency of the reinforced agitations which 

 enables them to take possession of the nerve-paths by which 

 muscles are reached. 



It is for the psychologist to define the application of the 

 terms " consciousness," " attention," " will." He cannot 

 define the attributes of the ego which these terms connote. 

 The moralist must show the way in which they determine, or 

 should determine, conduct. Yet within the plain limits of 

 physiology, attention, using the word in its every-day sense, 

 modifies the responses of the nervous system in a degree which 

 cannot escape observation. It is astonishing to anyone accus- 

 tomed to hospital surgery (although even in this field singular 

 exceptions are met with) to see the grave operations which a 

 veterinary surgeon may perform, without the animal showing 

 any evidence of pain, provided its apprehension has not been 

 aroused and its attention directed to what is being done. A 

 horse standing in front of a crib of oats, untied, will hardly 

 whisk its tail while the surgeon is making a great wound in its 



