James attended most of the University classes, but studied surgery under the great Robert Liston, the foremost extra-mural surgeon, daring and skilful as an operator and of great repute as a lecturer, who afterwards filled the post of Professor of Clinical Surgery in University College Hospital, London. Liston was an abrupt-mannered but sincere man, and a keen lover of truth. He was a warm advocate of hospital reform, and was successful in introducing several needed improvements into the Royal Infirmary after a fierce fight. Here again Simpson was brought under the influence of a strong, self-reliant man with a distinct tendency towards controversy; to whom he was also attracted by the fact that Liston was a native of Linlithgowshire. Liston and Syme, after being close colleagues, quarrelled most fiercely, and were bitter rivals until Liston removed to London in 1835. Simpson attended Liston's lectures during three sessions. There is no record of his having obtained great distinction in any of the medical classes, but his certificates show that he worked with pre-eminent diligence in them all, and obtained a characteristic mastery of each subject. If any exception occurred it was in the very subject in which he afterwards earned his greatest scientific fame--that of obstetrics. He attended Professor James Hamilton's course of lectures on that subject early in his career, and apparently felt so little interest--the subject only became a compulsory one for examination for qualification in 1830--that he regularly went to sleep during the lecture. The excuse urged was that the lecture being a late one, three to four in the afternoon, it found him tired out after a long morning of study, lectures, and practical work. But had he been keenly interested he would have been wide awake, for Hamilton was a forcible, if plain, lecturer.