Bruce insisted on the antiquity of his family, but was poor. At Edinburgh university he was ‘distinguished for his abilities and extensive erudition’ and published his lectures as First Principles of Philosophy (1780) and Elements of the Science of Ethics (1786). As tutor to Robert Saunders Dundas, whom he accompanied to Göttingen, he was rewarded with a joint grant of the reversion of the patent of King’s printer and stationer for Scotland. Henry Dundas employed him as historiographer of the East India Company: after three years’ research his Historical View of Plans for the Government of British India was published in 1793, when his appointment became official. In 1796 he produced a historical Review of the balance of power in Europe. Dundas formed the view that Bruce’s sole joy was to be ‘buried in old records’. In 1798 his Report on home defence arrangements in 1588 was supposed to have inspired Pitt’s. He next produced a voluminous report on the Anglo-Scottish union of 1707, commissioned by the Duke of Portland to throw light on the projected union with Ireland (1799). By then Dundas thought his services as a government publicist should be rewarded and, as intended for him seven years before, he became Latin secretary to the Privy Council and keeper of the State papers for life (£500 p.a.). According to the Speaker, writing in 1806, he introduced confusion into the State paper office. That year, as an East India Company stockholder, he was entitled to three votes for the directorate. In 1810 appeared his Annals of the East India Company in three volumes.
Bruce was already in Parliament, having been returned as a friend of ministers by (Sir) Christopher Hawkins, for whom in return he secured patronage from Lord Melville.
In 1814 he retired from Parliament to supervise the Stationery Office in Edinburgh: he also ‘applied himself to being a country gentleman as he had in other pursuits’. He died 16 Apr. 1826 ‘in his 82nd year’, having been for some time ‘the only surviving member of that great literary phalanx which adorned the Scottish metropolis’. He left his estate to his brother’s natural daughter Margaret Stuart Bruce and £2,000 to Robert, Viscount Melville.
