February 23, 1905] 



NATURE 



405 



imagined that he had discovered a method by which scien- 

 tific truth might be determined with absolute certainty, 

 and by a mechanical mode of procedure such that all men 

 were capable of employing it. " Our method of discover- 

 ing the sciences is," he says, " one which leaves not much 

 to sharpness and strength of wit, but nearly levels all wits 

 and intellects." And this opinion is endorsed by most 

 writers of the empiricist school in complete disregard of 

 the teaching of history. Those who imagine that science 

 requires nothing but the registering and classification of 

 facts forget that the facts observed can only be connected 

 and related by the mind, and that the laws of nature are 

 after all mental products from given data. 



Not only did John Hunter not follow the mechanical 

 methods of Francis Bacon, but it is the worl< of the mind 

 which is the peculiar characteristic of his method and its 

 chief glory. Others could do as well as he the more 

 mechanical part of his task — indeed, much of it was done 

 by others ; but the suggesting, controlling, coordinating 

 mind was Hunter's, which, amidst the multiplicity of 

 phenomena and of data apparently conflicting, discovered 

 unity amidst multiformity, which is the special function of 

 science. 



John Hunter's constant aim was to arrive at principles, 

 and he was distrustful of so-called facts. " The principles 

 of our art," he said, " are not less necessary to be under- 

 stood than the principles of other sciences ; unless, indeed, 

 the surgeon should wish to resemble the Chinese philo- 

 sopher whose knowledge consisted only in facts. In that 

 case the science must remain unimproved until new facts 

 arise. In Europe philosophers reason from principles, and 

 thus account for facts before they arise." 



Hunter possessed every moral and intellectual qualifi- 

 caticn necessary for useful scientific research. He had a 

 large knowledge of facts based on an intimate acquaintance 

 with the phenomena of organic nature. He had a fertile 

 imagination ready to suggest possible relations of those 

 facts. He had openness of mind, and a conscientious 

 scientific spirit which submitted every hypothesis to the 

 test of observation and experiment. Scepticism is the first 

 condition of reasoned knowledge. Hunter was not only 

 observant, but he was rationally sceptical and critical, and 

 he himself ascribed his success as a scientific investigator 

 to the sceptical qualities of his mind. He took nothing on 

 trust. He was always careful to distinguish between mere 

 conjecture and reality, and drew a sharp distinction between 

 the actual results of an experiment physically performed 

 and what might have been mentally anticipated. " In pur- 

 suing any subject," he says, " most things come to light 

 as it were by accident, that is, many things arise out of 

 investigation that were not at first conceived, and even 

 misfortunes in experiments have brought things to our 

 knowledge that were not, and probably could not have 

 been, previously conceived ; on the other hand, I have often 

 devised experiments by the fireside or in my carriage, and 

 have also conceived the result ; but when I tried the experi- 

 ment, the result was different, or I found that the experi- 

 ment could not be attended with all the circumstances that 

 were suggested." Here, in a sentence, we note the wide 

 difference between the modern and the mediasval spirit in 

 science. The alchemists performed experiments innumer- 

 able, but with them theory ranked above experiment, and 

 if experin-.ent gave an unexpected result, this was forced 

 into an artificial conformity with the apriorislic theory. It 

 was therefore, says Lange in his " History of Mate- 

 rialism," " essentially directed to the production of this 

 previously anticipated result rather than to free investi- 

 gation." 



While Hunter was intolerant of a state of doubt in small 

 things as in great, if by any means decision was possible,, 

 be ever held his judgment in suspense if certainty was not 

 -attainable. Like all strong characters, he cared little for 

 systems or consistencies of opinion. He followed wherever 

 Truth should lead, and by his very nature was always open 

 to new and higher knowledge. To a pupil who asked with 

 surprise whether he had not the year before stated an 

 opinion on some point directly at variance with one he had 

 just put forth, he boldly replied: "Very likely I did; I 

 hope I grow wiser every year." And again: " Never ask 

 me what I have said, or what I have written ; but if you 

 will ask me what my present opinions are I will tell you." 

 In attempting an appreciation of John Hunter's method 



NO. 1^43, VOL. 71] 



I have suggested rather than explained the development and 

 growth of the modern knowledge of physics, chemistry, 

 and biology under the influence of the experimental 

 method ; but it has not been my purpose or intention to 

 offer any defence of this method. To defend the use of 

 experiment in physics and in chemistry would be manifestly 

 absurd, and I assume that in this place and before this 

 audience it is equally unnecessary to offer an apology for 

 its use in physiology and pathology. I opine, however, 

 that it is within my province as Hunterian orator to antici- 

 pate the possible censure of some who would not hesitate 

 in the sacred name of religion to traduce the memory of 

 Hunter because he practised experiments in physiology. 

 John Hunter did employ the method of experiment. He 

 employed it no less with zeal than with intelligence. He 

 employed it not from idle curiosity, not from the prompt- 

 ings of vainglory, or for the purposes of worldly advance- 

 ment ; all that he had he gave to science. He employed it 

 in the service of humanity and in the study of the nature 

 and laws of life; and the knowledge which he thereby 

 acquired he transferred to the domain of medicine and 

 surgery, and applied to the alleviation of sickness and 

 suffering among animals no less than among men. 



I pretend not either impiously to affirm or not less 

 impiously lo deny all the purposes of infinite wisdom in 

 giving man dominion over the fish of the sea, and over the 

 fowl of the air, and over every living thing that moveth 

 upon the earth ; but we do know that throughout historic 

 time man has not hesitated to capture, to subjugate, and 

 to slay, beast and bird and fish, for his pleasure, his 

 sustenance, and his service. Was the lordship over the 

 animals given to man only for the satisfying of his physical 

 and sensuous needs? Is not the life more than food? Was 

 it only with reference to man's bodily well-being that the 

 question was asked : Are ye not of much more value than 

 the birds of the heaven? Does the mind need no aliment? 

 And is the veto to be applied only when animals are to be 

 used for the purposes of elucidating the kindly functions 

 of physiology, or of disclosing the baneful secrets of 

 disease ? 



The vicarious suffering and sacrifice of animals for the 

 service and the salvation of man have obtained throughout 

 the ages, and constituted the basis of the elaborate cere- 

 monial system of the ancient Israelites. In anticipation of 

 the great Passover, Moses directed the Israelites each to 

 kill a lamb according to their families, and to sprinkle 

 its blood upon the lintel and the two side posts. " For 

 the Lord will pass through to smite the Egyptians ; and 

 when He seeth the blood upon the lintel, and on the two 

 side posts, the Lord will pass over the door, and will not 

 suffer the destroyer to come into your houses to smite 

 you." The complete purification of one leper and his re- 

 ception back into society involved not only the slaughter 

 of three lambs, but the convalescent had to appear with 

 two living clean birds, one of which was slain, while the 

 other, still living, was baptised in the dead bird's blood, 

 and then allowed to fly away free. The principle of sub- 

 stitution was actualised in the ceremony of the scapegoat. 

 At the annual Feast of Expiation, a young bullock, two 

 kids, and one ram were slain ; and two goats were taken 

 upon which lots were cast, one lot for Yahwe, the other 

 for Azazel. The goat on which the lot fell for Yahwfe 

 was sacrificed for a sin offering ; but the goat upon which 

 the lot fell for Azazel was presented alive, and when the 

 high priest had symbolically placed upon its head the sins 

 and transgressions of all the people, the goat was led 

 into the desert, there to become the victim of hunger and 

 thirst, and the prey of ravenous bird and beast. 



Are these hecatombs to be regarded as of Divine origin 

 and sanction, while the inoculation of a cat or dog, or it 

 may be a rat, is to be denounced as a desecration and a 

 violation of the purposes and will of God ? Who will say 

 but that in our day, as the Angel of Death passes through 

 the land, seeing upon us the sprinkling of the immunising 

 blood, takes that for a token, and is not suffered to come 

 into our houses to smite us? " Dipt in his fellow's blood 

 the living bird went free " ; and so we, dipped in blood, 

 aye, the blood of our fellow-man, as the annals of medical 

 martyrology bear witness, we enjoy a growing freedom 

 from plague and pestilence and noisome disease, and in the 

 fulness of knowledge the measure of bur freedom will be 

 full. 



