20 



my endeavour to show that these judgments are 

 historically justifiable. 



To put the discovery of the systemic circu- 

 lation of the blood in its true light, we must 

 have some notion of the history of philosophy, 

 science and medicine. Medicine, and herein it is 

 in contrast with Theology and Law, had its sources 

 almost wholly in the Greeks. Not only in the 

 doctrine of the four elements of Empedocles, a 

 doctrine which has survived almost to our own 

 day 1 , and in the physical theories of Heraclitus 

 and Leucippus, did medicine, for good or ill, first 

 find a scheme of thought, but in the schools of 

 Hippocrates and of Alexandria it was based also, 

 and far more soundly, upon natural history and 

 anatomy. The noble figure of Galen, the first experi- 

 mental physiologist and the last of the great Greek 

 physicians, portrayed for us by Dr Payne in the 

 Harveian Oration of 1896, stood eminent upon the 



1 The "humoral doctrine" is imperfectly known. The four 

 elements are earth, water, air, fire ; the four qualities are hot, 

 cold, moist, dry ; the four humours are blood, phlegm, yellow 

 bile, black bile. By permutation of these were obtained the 

 endless elaborations of the galenist doctrine which for many 

 centuries blinded Europe not to the truth only, but also to 

 the clinical and physiological methods, example, and attain- 

 ments of Galen himself. 



