He became the schoolmaster of the parish of Fordoun in 1753. He took the position of usher at the grammar school of Aberdeen in 1758. In 1760, he was, to his surprise, appointed
Professor of Moral Philosophy at
Marischal College (later part of
Aberdeen University) as a result of the influence exerted by his close friend, Robert Arbuthnot of Haddo. In the following year, he published a volume of poems,
The Judgment of Paris (1765), which attracted attention. But the two works that brought him most fame were
An Essay on the Nature and Immutability of Truth, and his poem of
The Minstrel. The
Essay, intended as an answer to
David Hume, had great immediate success, and led to an introduction to the King, a pension of £200, and the degree of
LL.D. from
Oxford. The first book of
The Minstrel was published in 1771 and the second in 1774, and constitutes his true title to remembrance, winning him the praise of
Samuel Johnson. It contains much beautiful descriptive writing. Beattie was prominent in arguing against the institution of
slavery, notably in his
Essay on the Nature and Immutability of Truth (1770), and in
Elements of Moral Science (1790–93), where he used the case of
Dido Belle to argue the mental capacity of black people. Beattie was an amateur cellist and member of the Aberdeen Musical Society. He considered questions of music philosophy in his essay
On Poetry and Music (written 1762, published 1776), which was republished several times and translated into French in 1798. His poem "The Hermit" was set to music by
Tommaso Giordani (1778). Beattie co-founded the
Royal Society of Edinburgh in 1783. He was elected to the
American Philosophical Society in 1786. ==Personal life==