“If we ask what gave him that most valuable power of estimating what was worth doing, and what could be done—the power which Bacon calls the ‘mathematics of the mind’—we find the reply, I believe, in these great facts of his history. Firstly, that he was a man who had a free youth, not over-taught, nor over-strained; and, secondly, that in his manhood he worked with an eye to usefulness and duty, and not only to notoriety, nor to the mere cry of ‘who will show us something new?’ Indeed, the main and distinctive feature of his noble life was his resolute pursuit of the practical aim of his profession, to establish sound laws for scientific surgery and medicine. I have said that the wonderful store of facts he collected constituted answers to questions: Hunter the physiologist answering the questions of Hunter the surgeon. He did not so follow physiology as to turn it away from usefulness. And the results of his work he puts up in his museum. And he will gladly have anything for his collection. But always putting things by in their physiological order, mark, so that in due time they shall answer to his further questions. He will lecture on surgical principles,—true ones they must be,—if he changes them yearly in accordance with his observations. But he will not, he cannot, lecture on comparative anatomy or zoology. Why not? It does not conform enough with his main bent to surgery, to practical aim, to a duty. He believes in a vital principle, therefore he must have an aim before him. He succeeds in his aim; and by the masterly introduction of the operation on aneurism which bears his name he saves thousands from a painful death. Led further by the same enthusiasm for the true purpose of his life as a surgeon, he inoculates his frame with a loathsome disease that he may have it always by him to study it, regardless of danger and of pain.” Sir James Paget’s views[16] are thus expressed:— “The range of Hunter’s work matched with the time devoted to it. Never before or since—I think I am safe in saying this—was any one a thorough investigator and student in so wide a range of science. He was an enthusiastic naturalist; as a comparative anatomist and physiologist he was unequalled in his time; among the few pathologists he was the best; among the still fewer geologists and students of vegetable physiology, he was one, if not the chief; and he was a great practical surgeon. He was surgeon to a large hospital in London, and for many years held the largest practice in the metropolis. In all these things at one time no one but Hunter ever was eminent and successful.... There is not one of them in which he did not make investigations wholly original—not one of them of which he did not enlarge the area very far beyond that which had been covered by his predecessors—not one of them in which he did not leave facts and principles on record which it is impossible to count and very hard to estimate.