With the end of this tour, Simpson brought to a close the more strictly student part of his career, although it remained true of him, as of all eminent scientific men, that he was a student to the end of his days. He felt himself now fully equipped to enter into the professional battle, and he stepped into the arena, not only full of vigorous life and hope, but possessed of highly trained faculties, keen senses, and lofty ideals. It was his strong, personal characteristics, apart from his accomplishments, which at once placed him head and shoulders above his fellows. "He had a great heart," says a recent writer, "and a marvellous personal influence, calling forth, not only the sympathy and love of his fellowmen, but capable of kindling enthusiasm in others almost at first sight." It is impossible to overestimate this personal influence in analysing the elements of his ultimate success, and it is more impossible for those who did not feel it to realise its nature; but that he became the beloved as well as the trusted physician is due to this influence. "He had no acquaintances," says the writer already quoted; "none could come into contact with him and stop short of friendship." This was a powerful trait to possess; it cannot be denied that he was fully aware of it and its value; and used it with good effect in establishing himself as the greatest physician of his day. As a scientist he started with an eager desire for knowledge and reverence for truth, to which was added the highly developed power of mental concentration born of early self-training. When most men would be waiting in what they would term enforced idleness, Simpson would be busy with book or pen, deeply attentive to his occupation despite surrounding distractions or temptations to frivolous idleness. He took the full measure of the value of Time and handled his moments as another would a precious metal. "At all times," he said himself, "on all occasions, and amidst the numerous disturbing influences to which the medical man is so constantly subjected, he should be able to control and command his undivided mental attention to the case or object that he may have before him.... In the power of concentrating and keeping concentrated all the energies of attention and thought upon any given subject, consists the power of thinking strongly and successfully upon that subject. The possession or the want of this quality of the mind constitutes the main distinction between the possession or the want of what the world designates 'mental abilities and talents.'"