There is reason to believe that his conclusion is erroneous, and that different diseases can so accompany each other, as to be united in the same individual, at the same time, and in the same part.283 Whether or not

this be the case, it is equally interesting to notice the process of thought which led Hunter to bestow infinitely more pains in arguing from the general theory, than in arguing to it. Indeed, he can hardly be said to have argued to it at all, since he obtained it by a rough and hasty generalization from what seemed to be the obvious properties of inorganic matter. Having thus obtained it, he applied it to the pathological phenomena of the organic world, and especially of the animal world. That he should have adopted this course, is a curious proof of the energy of his deductive habits, and of the force of mind which enabled him so to set at naught the traditions of his English contemporaries, as to follow a method which, in the opinion of every one who surrounded him, was not only full of danger, but could never lead to truth.

therefore, are often supposed to be mixed, and to exist in the same part. Thus we hear of a pocky-scurvy, a pocky-itch, rheumatic-gout, &c. &c., which names, according to my principle, imply a union that cannot possibly exist." Ibid., vol. iii. pp. 3, 4.

283 Dr. Robert Williams (Encyclopædia of the Medical Sciences, London, 1847, 4to, p. 688) says, "The diagnosis between gout and rheumatism is often exceedingly difficult, so much so that nosologists have given a mixed class, or rheumatic gout. Mr. Hunter warmly opposed this compound appellation, for, in his opinion, no two distinct diseases, or even distinct diatheses, can co-exist in the same constitution; a law, it must be admitted, to have many exceptions." Compare Watson's Principles and Practice of Physic, London, 1857, vol. i. p. 312; “acting upon the aphorism of John Hunter (an aphorism, however, which requires some qualification), that two diseases or actions cannot go on in a part at the same time.” According to another authority, "There can be little doubt that two or more zymotic processes do often go on simultaneously in the blood and body; a fact of profound interest to the pathologist, and worthy of attentive investigation." Report on the Public Health for 1847, in Journal of the Statistical Society, vol. xi. p. 168, London, 1848. See also, on the co-existence of specific poisons, Erichsen's Surgery, 2d edit. London, 1857, p. 430. Mr. Paget, in his striking, and eminently suggestive Lectures on Pathology, London, 1853, vol. ii. pp. 537, 538, has made some interesting remarks on one part of the theory of co-existence; and his observations, so far as they go, tend to corroborate Hunter's view. He has put very forcibly the antagonism between cancer and other specific diseases; and especially between the cancerous diathesis and the tuberculous.

Other parts of his pathology abound with similar instances, which show how anxious he was to assume principles on which he could build arguments. Of this kind, were his ideas respecting sympathy, as connected with action. He suggested, that the simplest forms of sympathy would probably be found in the vegetable world, because there, the general arrangements are less intricate than in the animal world.284 On this supposition, he constructed a series of curious and refined speculations, of which, however, I must confine myself to giving a very short summary. As animals sympathize more than vegetables, this helps us to understand why it is that their movements are more numerous. For, sympathy, being a susceptibility to impression, is also a principle of action.285 Like other principles of action, it may be either natural or diseased.286 But, whichever it be, it can, in plants, have only one mode of development, because, in them, it can only be influenced by stimulus; while in animals, which have sensation, it has necessarily three modes, one from stimulus, one from sensation, and a third compounded of the other two.287 These are the largest divisions of sympathy, if we consider the organic world as a whole. In single cases, however, sympathy admits of still further subdivision. We may reason from it, in reference to the age of the individual;288 we

284 The most simple sympathy is perhaps to be found in vegetables, these being much more simple than the most simple animal." Principles of Surgery, in Hunter's Works, vol. i. p. 327.

285

p. 318.

"This principle of action, called sympathy," &c. Ibid., vol. i. 286Sympathy may be divided into two kinds, the natural and the diseased." Principles of Surgery, in Hunter's Works, vol. i. p. 320; see also A Treatise on the Blood, Inflammation, &c., in Works, vol. iii. p. 6.

287 Croonian Lectures on Muscular Motion, in Hunter's Works, vol. iv. p. 207; and exactly the same words in his Phytology, in Hunter's Essays, London, 1861, vol. i. p. 361.

288 Local or partial sympathy is found more in old than in young; whereas universal sympathy is more in young than in old. Sympathy is less determined in young persons, every part being then ready to sympathize with other parts under disease. "As the child advances, the power of sympathy becomes partial, there not being now, in the constitution, that universal consent of parts, but some part, which has greater sympathy than the rest, falls into the whole irritation; therefore the whole disposition to sympathy is directed to some particular part. The different organs acquire

290

may also reason from it in reference to temperament, since, in point of fact, temperament is nothing but susceptibility to action.289 And when sympathy is in action, we may, by analyzing our idea of it, reduce it to five different heads, and may classify it as continued, or contiguous, or remote, or similar, or dissimilar.2 All these supplied Hunter with principles from which, by reasoning deductively, he attempted to explain the facts of disease; for, according to him, disease merely consists in a want of combination of actions.291 By this process of thought, he was induced to neglect those predisposing causes, to which inductive pathologists pay great attention, and with which the works of his English contemporaries were much occupied. Such causes could only be generalized from observation, and Hunter made no account of them. Indeed, he even denies their real existence, and asserts that a predisposing cause, is simply an increased susceptibility to form disposition to action.292

more and more of their own independent actions, as the child grows older." Hunter's Works, vol. i. pp. 322, 323.

66

289 Susceptibilities for dispositions and actions appear to me to be the same with what are usually understood by temperament. Temperament is the state of the body fitting it for the disposition or action it is then in." Hunter's Works, vol. i. p. 307.

290 Hunter's Works, vol. iii. p. 393.

291

"As every natural action of the body depends, for its perfection, on a number of circumstances, we are led to conclude, that all the various combining actions are established while the body is in health, and well disposed; but this does not take place in diseased actions, for disease, on the contrary, consists in the want of this very combination." Hunter's Works, vol. iii. p. 10. Compare vol. i. p. 310: "I have explained that a disease is a disposition for a wrong action, and that the action is the immediate effect of the disposition, and that either the actions, or the effects of those actions, produce the symptoms which are generally called the disease; such as sensations, which are commonly pain of all kinds, sickness, alteration visible or invisible in the structure of the part or parts that act, and sympathy."

292There is no such thing, strictly speaking, as a predisposing cause. What is commonly understood by a predisposing cause is an increased susceptibility to form disposition to action. When I say I am predisposed for such and such actions, it is only that I am very susceptible of such and such impressions." Hunter's Works, vol. i. p. 303. See also p. 301: "The most simple idea I can form of an animal being capable of disease is, that every animal is endued with a power of action, and a susceptibility of

By reasoning from the twofold ideas of action and of sympathy, Hunter constructed the deductive or synthetic part of his pathology. This he did as a Scotchman, and to this, had he always lived in Scotland, he would probably have confined himself. But being for forty years surrounded by Englishmen, and having his mind impregnated by English habits, he contracted something of their mode of thought. We, accordingly, find that a considerable portion of his pathology is as inductive as the most eager disciple of Bacon could desire; forming, in this respect, a striking contrast to the purely synthetic method of Cullen, the other great pathologist of Scotland. In the attempt, however, which Hunter made to mix these two methods, he perplexed both himself and his readers. Hence that obscurity, which even his warmest admirers have noticed, though they have not perceived its cause. Vast as his powers were, he was unable to effect a complete union between induction and deduction. That this should have happened, will not surprise any one, who considers how some of the greatest thinkers have failed in this, the most difficult of all enterprises. Among the ancients, Plato failed in induction, and all his followers failed with him; since none of them have placed sufficient confidence in facts, and in the process of reasoning from particulars to generals. Among the moderns, Bacon was deficient in deduction, and every Baconian has been similarly deficient; it being the essential vice of that school to despise reasoning from general propositions, and to underrate the value of the syllogism. It may, indeed, be doubted if the history of the world supplies more than two instances of physical philosophers being as great in one form of inves tigation as in the other. They are Aristotle and Newton, who wielded each method with equal ease, combining the skill and boldness of deduction with the

impression, which impression forms a disposition, which disposition may produce action, which action becomes the immediate sign of the disease; all of which will be according to the nature of the impression and of the part impressed."

caution and perseverance of induction, masters alike of synthesis and of analysis, as capable of proceeding from generals to particulars, as from particulars to generals, sometimes making ideas precede facts, and sometimes making facts precede ideas, but never faltering, never doubting which course to take, and never allowing either scheme unduly to encroach on its opposite. That Hunter should be unable to perform this, merely proves that he was inferior to these two men, whose almost incredible achievements entitle them to be termed the prodigies of the human race. But what he did was wonderful, and, in his own department, has never been rivalled. Of the character and extent of his inquiries, I have given a sketch, which, notwithstanding its imperfections, may serve to illustrate the antagonism of the Scotch and English intellects, by showing how the methods peculiar to each nation struggled for mastery in that great mind, which was exposed to the action of both. Which method predominated in Hunter, it would be hard to say. But it is certain, that his understanding was troubled by their conflict. It is also certain, that, owing to his love of deduction, or of reasoning from general ideas, he exercised much less sway over his English contemporaries, than he would have done if he had exclusively followed their favourite method of reasoning from particular facts. Hence, the disproportion between his influence and his merits. As to his merits, it is now admitted, that, in addition to his physiological discoveries, and the great pathological views which he propounded, we may trace to him nearly all the surgical improvements which were introduced within about forty years after his death.293 He was the first who explained,

293 Hunter died in 1793. In 1835, Mr. Palmer writes: "Those who have traced the progress of modern surgery to its true source, will not fail to have discerned, in the principles which Hunter established, the germs of almost all the improvements which have been since introduced." Hunter's Works, vol. i. p. vii. Eighteen years later, Mr. Paget says of Hunter's views respecting the healing of injuries: "In these sentences, Mr. Hunter has embodied the principle on which is founded the whole practice of subcutaneous surgery; a principle of which, indeed, it seems hardly possible to exaggerate the importance." Paget's Lectures on Surgical Pathology,