[816] I mean, of course, to apply this remark only to the globe we inhabit, and not to extra-terrestrial phenomena. Respecting the organization or non-organization of what exists out of this earth, we have no evidence, and can hardly expect to have any for centuries. Inferences have, indeed, been drawn from telescopic observations; and attempts are now being made, abroad, to determine, by a still more refined process, the physical composition of some of the heavenly bodies. But without venturing, in this note, to enter into such discussions, or even to state their purport, I may say, that the difficulty of verification will long prove an insuperable barrier to our knowledge of the truth or falsehood of any results which may be obtained.
[817] Mr. Simon, in his thoughtful and suggestive Lectures, says, ‘We may describe Pathology to consist in the Science of Life under other conditions than those of ideal perfection.’ Simon's Lectures on Pathology, London, 1850, p. 14. This is by far the best description I have met with; though, as it involves a negative, it cannot be accepted as a definition. Indeed, the context shows that Mr. Simon does not suppose it to be one.
[818] I formerly adopted the commonly received division of organic statics, and organic dynamics; the statics being anatomy, and the dynamics being physiology. But, I now think that our knowledge is not sufficiently advanced to make this so convenient as the division into physiological and pathological, or into normal and abnormal, provided we remember that in reality nothing is abnormal. The practically useful, but eminently unscientific, doctrine, that there can be alteration of function without alteration of structure, has effaced some of the most essential distinctions between anatomy and physiology, and especially between morbid anatomy and morbid physiology. Until those distinctions are recognized, the scientific conceptions of professional writers must be confused, however valuable their practical suggestions may be. While men are capable of believing that it is possible for variations of function to proceed from any cause except variations of structure, the philosophic importance of anatomy will be imperfectly appreciated, and its true relation to physiology will remain undefined. Inasmuch, however, as, with our actual resources, the most careful dissection is often unable to detect (in insanity, for instance) those changes of structure which produce changes of function, superficial thinkers are placed under a strong temptation to deny their invariable connexion; and while the microscope is so imperfect, and chemistry so backward, it is impossible that experiments should always convince them of their mistake. Hence, I believe that until our means of empirical research are greatly improved, all such investigations, notwithstanding their immense value in other respects, will tend to lead mere inductive minds into error, by making them rely too much on what they call the facts of the case, to the prejudice of the reason. This is what I mean by saying, that our knowledge is not sufficiently advanced to make it advisable to divide the sciences of organic bodies into physiological and anatomical. At present, and probably for some time yet, the humbler division into physiological and pathological, may be deemed safer, and more likely to produce solid results.
[819] Hunter, as we shall presently see, did take an extraordinarily comprehensive view of pathology, including the whole of the organic world and even the aberrations of form in the inorganic.
[820] Thomson's Life of Cullen, vol. i. p. 70, Edinburgh, 1832.
[821] Thomson's Life of Cullen, vol. i. p. 96. Bower states that Cullen ‘was appointed to the chair in 1755.’ Bower's History of the University of Edinburgh, vol. ii. p. 216, Edinburgh, 1817.
[822] ‘It seems impossible to peruse the passages I have quoted from Dr. Cullen's manuscript lectures and papers, and from his Essay on Evaporation, without perceiving that his investigations with regard to the heat and cold occasioned by the combination, liquefaction, and evaporation of bodies, must not only have assisted to direct the attention of his pupil Dr. Black to similar inquiries, but must also have furnished him with several of the data from which his simple and comprehensive theory of Latent Heat was afterwards so philosophically deduced.’ Thomson's Life of Cullen, vol. i. p. 56.
[823] ‘It is allowed by the admirers of this great man, that he was perhaps too fond of theory.’ Bower's History of the University of Edinburgh, vol. iii. p. 273
[824] In 1759, he wrote to Dr. Balfour Russell, one of his favourite pupils: ‘You will not find it possible to separate practice from theory altogether; and therefore, if you have a mind to begin with the theory, I have no objection.’ Thomson's Life of Cullen, vol. i. p. 130. Compare his Introductory Lectures to the Practice of Physic, where, asserting truly, ‘that reasoning in physic is unavoidable’ (Cullen's Works, vol. i. p. 417), he boldly infers, ‘that to render it safe, it is necessary to cultivate theory in its full extent.’
[825] Even Cullen himself says, rather roughly, ‘The great horde of physicians are always servile imitators, who can neither perceive nor correct the faults of their system, and are always ready to growl at, and even to worry, the ingenious person that could attempt it. Thus was the system of Galen secured in the possession of the schools of physic, till soon after the irruption of the Goths and Vandals destroyed every vestige of literature in the western parts of Europe, and drove all that remained of it to seek a feeble protection at Constantinople.’ Lectures Introductory to the Practice of Physic, in Cullen's Works, vol. i. p. 386, Edinburgh, 1827.