REPORT OX ANIMAL PHYSIOLOGY. 99 



was valuable in the doctrines which they had adopted from the 

 philosophers of Greece and Ionia, became obscure and vitiated 

 by the additions of sophists ; and experiment and anatomy, which 

 had once been so highly cultivated by Erasistratus and Hero- 

 philus, fell nearljMnto disuse. I pass over, therefore, the vaunted 

 restoration of the Hippocratic method by Scrap ion, the pupil of 

 Herophilus, in the empiric school which rejected reasoning al- 

 together, and affected to rely upon experience. I pass over, also, 

 the methodic school of Asclepiades, which attributed, after De- 

 mocritus, all natural phasnomena to the fortuitous concourse of 

 atoms, and the existence of bodies to the conjunction of these in 

 a certain form, and their functions to the mechanical aggregation 

 and separation of the same. Their doctrines have thrown no 

 light on our science. Each of these schools, and others like them, 

 had credit for a time ; because, as they arose, men hoped to re- 

 pose in them, wearied with balancing theories which, being 

 founded on no extensive induction, and few just analogies, were 

 not unfrequently at the same time false generalizations of the 

 scanty instances upon which they were raised, and therefore ne- 

 cessarily contradictory. 



The school founded by Galen has a just claim to the title of 

 eclectic, which had been assumed by another ; for its doctrines 

 were a mixture of the philosophy of Plato, of the physics and 

 logic of Aristotle, and of the practical knowledge of Hippocrates. 

 He perceived the objection to Aristotle's theory, that it included 

 under a generic term the organic functions of plants and animals, 

 together with their inanifestations of sense and intelligence*. He 

 therefore proposed another arrangement of the phaenomenaof life, 

 which deserves to be recorded, in as much as it contains the germ 

 of all those different classifications of the functions which have 

 prevailed in modern times. It is founded on the essential differ- 

 ence of the functions : first, that some are constantly necessary 

 for the support of life, and can never be suspended ; secondly, 

 that some ai'e accompanied by consciousness, and are subject to 

 the will. The vital functions are those which cannot be inter- 

 rupted without inducing death ; the animal, those which are 

 perceived, and for the most part voluntary j the natural, those 

 which proceed irresistibly, and without the consciousness of the 

 individual. These logical abstractions gave rise, unfortunately, 

 to the invention of corresponding imaginary principles as their 

 cause. Galen considered the heart, the liver, the brain to be re- 

 spectively the centres of these principles, — the occult powers dis- 

 tributing their influences in proportion to the elementary qualities 

 of those centres from which they emanated. He recognised, with 



• Thompson's Life of Cullen. 



h2 



