In 1772 Hunter began to lecture on the theory and practice of surgery, at first to his pupils and a few friends admitted gratuitously, but afterwards on payment of a fee of four guineas. This may be accounted the first introduction into this country, perhaps to any, of the idea of principles of surgery, and the necessity of a rational explanation of processes of repair, and of a scientific basis for operations. Instead of a study of anatomy alone being required by a surgeon, he elevated pathology into its true position, and brought in all the aids with which physiology and comparative anatomy could at that time illuminate the subject. But in advance of any of these aids was his own clear insight, which penetrated to the core of a question, and often brought out truth which he could not himself explain, or only imperfectly. He never overcame his difficulty in lecturing; at the commencement of each course he always composed himself by a draught of laudanum. His lectures, delivered on alternate evenings from October to April, were given from seven to eight o’clock. His class was usually comparatively small, never exceeding thirty; but the quality of his audience was good, as may be gathered from its having included Astley Cooper, Cline, Abernethy, Carlisle, Chevalier, and Macartney. He never became an attractive lecturer; from deficiency in extempore speaking, he was compelled to read his lectures, and seldom raised his eyes from his manuscript. His manner was frequently ungraceful, but his matter was for the most part highly intelligible and luminous to those of his hearers who came prepared by thought and attainments to be really edified, while he was often unintelligible to those who had no practice in thinking for themselves and desired to keep clear of that odious pain. In his lectures he was equally unsparing towards his own and others’ errors, and he never clung to his own past opinions. “Never ask me,” he replied to a question, “what I have said or what I have written; but if you will ask me what my present opinions are, I will tell you.”