'In recompense for so many mortifying things, which nothing but truth could have extorted from me, and which I could easily have multiplied to a greater number, I doubt not but you are so good a christian as to return good for evil, and to flatter my vanity, by telling me, that all the godly in Scotland abuse me for my account of John Knox and the reformation.'
Mr. Smith having completed, and given to the world his system of ethics, that subject afterwards occupied but a small part of his lectures. His attention was now chiefly directed to the illustration of those other branches of science which he taught; and, accordingly, he seems to have taken up the resolution, even at that early period, of publishing an investigation into the principles of what he considered to be the only other branch of Moral Philosophy,—Jurisprudence, the subject of which formed the third division of his lectures. At the conclusion of the Theory of Moral Sentiments, after treating of the importance of a system of Natural Jurisprudence, and remarking that Grotius was the first, and perhaps the only writer, who had given any thing like a system of those principles which ought to run through, and be the foundation of the law of nations, Mr. Smith promised, in another discourse, to give an account of the general principles of law and government, and of the different revolutions they have undergone in the different ages and periods of society, not only in what concerns justice, but in what concerns police, revenue, and arms, and whatever else is the object of law.
Four years after the publication of this work, and after a residence of thirteen years in Glasgow, Mr. Smith, in 1763, was induced to relinquish his professorship, by an invitation from the Hon. Mr. Townsend, who had married the Duchess of Buccleugh, to accompany the young Duke, her son, in his travels. Being indebted for this invitation to his own talents alone, it must have appeared peculiarly flattering to him. Such an appointment was, besides, the more acceptable, as it afforded him a better opportunity of becoming acquainted with the internal policy of other states, and of completing that system of political economy, the principles of which he had previously delivered in his lectures, and which it was then the leading object of his studies to perfect.
Mr. Smith did not, however, resign his professorship till the day after his arrival in Paris, in February 1764. He then addressed the following letter to the Right Honourable Thomas Millar, lord advocate of Scotland, and then rector of the college of Glasgow:—
'My Lord,—I take this first opportunity after my arrival in this place, which was not till yesterday, to resign my office into the hands of your lordship, of the dean of faculty, of the principal of the college, and of all my other most respectable and worthy colleagues. Into your and their hands, therefore, I do resign my office of professor of moral philosophy in the university of Glasgow, and in the college thereof, with all the emoluments, privileges, and advantages, which belong to it. I reserve, however, my right to the salary for the current half-year, which commenced at the 10th of October, for one part of my salary, and at Martinmas last for another; and I desire that this salary may be paid to the gentleman who does that part of my duty which I was obliged to leave undone, in the manner agreed on between my very worthy colleagues before we parted. I never was more anxious for the good of the college than at this moment; and I sincerely wish, that whoever is my successor, he may not only do credit to the office by his abilities, but be a comfort to the very excellent men with whom he is likely to spend his life, by the probity of his heart and the goodness of his temper.'
His lordship having transmitted the above to the professors, a meeting was held; on which occasion the following honourable testimony of the sense they entertained of the worth of their former colleague was entered in their minutes:—
'The meeting accept of Dr. Smith's resignation in terms of the above letter; and the office of professor of moral philosophy in this university is therefore hereby declared to be vacant. The university at the same time, cannot help expressing their sincere regret at the removal of Dr. Smith, whose distinguished probity and amiable qualities procured him the esteem and affection of his colleagues; whose uncommon genius, great abilities, and extensive learning, did so much honour to this society. His elegant and ingenious Theory of Moral Sentiments having recommended him to the esteem of men of taste and literature throughout Europe, his happy talents in illustrating abstracted subjects, and faithful assiduity in communicating useful knowledge, distinguished him as a professor, and at once afforded the greatest pleasure, and the most important instruction, to the youth under his care.'
In the first visit that Mr. Smith and his noble pupil made to Paris, they only remained ten or twelve days; after which, they proceeded to Thoulouse, where, during a residence of eighteen months, Mr. Smith had an opportunity of extending his information concerning the internal policy of France, by the intimacy in which he lived with some of the members of the parliament. After visiting several other places in the south of France, and residing two months at Geneva, they returned about Christmas to Paris. Here Mr. Smith ranked among his friends many of the highest literary characters, among whom were several of the most distinguished of those political philosophers who were denominated Economists.
Before Mr. Smith left Paris, he received a flattering letter from the unfortunate Duke of Rochefoucault, with a copy of a new edition of the Maxims of his grandfather. Notwithstanding the unfavourable manner in which the opinions of the author of that work were mentioned in the Theory of Moral Sentiments, the Duke informed Mr. Smith, on this occasion, that he had been prevented only from finishing a translation, which he had begun, of his estimable system of morals, into French, by the knowledge of having been anticipated in the design. He also observed, that some apology might be made for his ancestor, when it was considered, that he formed his opinions of mankind in two of the worst situations of life,—a court and a camp. The last communication Mr. Smith had with this nobleman was in 1789, when he gave him to understand, that he would no longer rank the name of Rochefoncault with that of the author of the Fable of the Bees; and, accordingly, in the first edition that was afterwards published of the Theory of Moral Sentiments, this promised alteration was made.
The next ten years of his life, after his arrival from the continent, Mr. Smith passed with his mother at Kirkaldy, though he occasionally, during that time, visited London and Edinburgh. Mr. Hume, who considered a town as the proper scene for a man of letters, made many attempts to prevail on him to leave his retirement.