Now this journey to London in 1761 is memorable because it constituted the economic "road to Damascus" for a future Prime Minister of England. It was during this journey, I believe, that Smith had Lord Shelburne for his travelling companion, and converted the young statesman to free trade. In 1795 Shelburne (then become Marquis of Lansdowne) writes Dugald Stewart: "I owe to a journey I made with Mr. Smith from Edinburgh to London the difference between light and darkness through the best part of my life. The novelty of his principles, added to my youth and prejudices, made me unable to comprehend them at the time, but he urged them with so much benevolence, as well as eloquence, that they took a certain hold which, though it did not develop itself so as to arrive at full conviction for some few years after, I can truly say has constituted ever since the happiness of my life, as well as the source of any little consideration I may have enjoyed in it."[120] Shelburne was the first English statesman, except perhaps Burke, who grasped and advocated free trade as a broad political principle; and though his biographer, Lord Edmond Fitzmaurice, attributes his conversion to Morellet, it is plain from the letter to Stewart that Morellet had only watered, it was Smith that sowed. It is important, therefore, to fix if possible the date of this interesting journey. It occurred, Lord Shelburne says, in his own youth, and the only journeys to London Smith made during the period which with any reasonable stretching may be called Shelburne's youth, were made in 1761, 1763, and 1773. Now we have no positive knowledge of Shelburne being in Scotland any of these years, but in 1761 his brother, the Hon. Thomas Fitzmaurice, who had been studying under Smith in Glasgow, and living in Smith's house, left Glasgow for Oxford; and Shelburne, who, since his father's death that very year, was taking, as we know from his correspondence with Sir William Blackstone on the subject, a very responsible concern in his younger brother's education and welfare, may very probably have gone to Scotland to attend him back. This circumstance seems to turn the balance in favour of 1761 and against the other two dates. It is almost certain that the journey was not in 1773, for Shelburne would hardly have thought of himself as so young at that date, six years after he had been Secretary of State, and besides he had probably cast off his prejudices by that time, and was already (as we shall presently find) receiving instruction from Smith on colonial policy in 1767; and whether it was 1761 or 1763, it in either case shows at what a long period before the appearance of the _Wealth of Nations_ Smith was advocating those broad principles which struck Shelburne at the time for their "novelty," and were only fully comprehended and accepted by him a few years afterwards.