x] of the Nervous System. 279 



" perceives that it feels, and in accordance with that perception 

 "is driven into various passions and actions, is turned to the 

 " desire of this or that object, and sometimes, as we may at 

 " times observe in certain beasts, in following up the thing 

 " sought for, enters upon and carries out acts which seem to 

 "have no other source than judgment and a ceHain deliberation. 

 " Of course in man we can readily understand that the rational 

 11 soul, the governor as it were, looks upon the images and 

 "impressions presented to the rational soul as to a mirror, 

 "and according to the conceptions and notions thus derived 

 " exercises the acts of reason, judgment and will. In what way 

 " however in brute beasts, perception, the discrimination of 

 " objects, desire, memory and other forms of so to speak lower 

 " reason, are carried out seems very difficult of explanation." 



Willis's views did not escape severe criticism on the part of 

 his contemporaries and even of his friends. John Mayow's 

 strictly scientific spirit led him to apply to Willis's rhetorical 

 expositions the following words : 



" We have no need of I know not what vital flame by whose 

 " deflagration the whole mass of the blood is heated, the heart 

 "living like a salamander untouched in the midst of the flames. 

 " Much less are we to suppose that such an intense heating of 

 "the blood takes place as to be strong enough to give rise to 

 " light, the rays of which, transmitted to the brain, are to 

 "be thought to form the sensitive soul." 



And again, 



"As regards this lucid soul which dwells in the brains of 

 " animals, I ask how it comes about that the light which is 

 " supposed to illumine the whole brain and all the nerves can 

 " never be seen by the eye ? Assuredly Fires of this kind and 

 " New Lights no less in Anatomy than in Religion appear to 

 " me things wholly vain and fanatic." 



The gifted Stensen also, in the remarkable lecture "On 

 the Anatomy of the Brain," to which I have already referred, 

 criticised very severely the views both of Descartes and of 

 Willis. The burden of the lecture is that the anatomy of the 

 brain is, for technical reasons, the most difficult part of all 

 anatomy, and that, in spite of all that has been done, our 



