288 The Older Doctrines [lect. 



his duties manfully during the great plague of 1665, was 

 President of the College of Physicians 1667-9, and passed 

 away at a ripe old age in 1677. 



He was a good anatomist and a sound physician ; and he is 

 perhaps best known for his classic works on rickets and on the 

 liver. With the latter I have dealt in speaking of Malpighi. 

 Yet the work to which he gave most of his energy, and 

 the one which best illustrates the character of his mind, is 

 the Tractatus de natura substantive energetica, published in 

 1672 when he was an old man. For, accurate and careful 

 anatomist though he was, Glisson was essentially a philosopher, 

 steeped in all the old Aristotelian learning which he had 

 eagerly devoured in his youth, and striving to shape that old 

 learning into accordance with the new philosophy which was 

 fermenting around him. The Tractatus in fact is a bold 

 attempt to shew that all phenomena as well as of living things, 

 be they animal or vegetable, as of things not alive, are the 

 successive developments of the one fundamental energy of 

 nature. He says of this work in his preface, " It treats of 

 " Nature, well known by name but really understood by few, 

 " that Nature of which so many splendid things have been said 

 " by ancient as well as modern Philosophers. But the few who 

 " have so far recognized this life of nature have neither 

 "made clear its substantial origin in material things nor 

 "adequately distinguished it from vegetable or animal life. 

 " Still less have they, following up its more hidden traces, in- 

 " quired how it is developed from the natural into the vegetable 

 " and animal. Least of all have they shewn how the material 

 " soul, the vegetative soul and the sensitive soul arise out of 

 " the life of nature, though this is lifted up by successive steps." 



He confesses that he has done no more than sketch out 

 the a priori proof of his view. The a posteriori proof has only 

 just been begun. That can not be supplied by an old man 

 like himself or indeed by the hands of any one man. " Let me 

 "hope that the Royal Society and other inquirers after truth 

 " will be moved to furnish it." 



I call attention to this general view of Glisson's, because 

 this was the mother idea which led him to a special conception 



