He was born in Glasgow, on Charlotte Street, the son of Kelso-born banker Alexander Blackie and Helen Stodart. He was educated at the New Academy and afterwards at the Marischal College, in Aberdeen, where his father was manager of the Commercial Bank. After attending classes at Edinburgh University, Blackie spent three years at Aberdeen as a student of theology. In 1829 he went to Germany, and after studying at Göttingen and Berlin he accompanied Bunsen to Italy and Rome. The years spent abroad extinguished his former wish to enter the Church, and at his father's desire he gave himself up to the study of law. He had already, in 1824, been placed in a lawyer's office, but only remained there six months. By the time he was admitted a member of the Faculty of Advocates he had acquired a strong love of the classics and a taste for letters in general. A translation of Goethe's Faust, which he published in 1834, met with considerable success, winning the approbation of Carlyle. After a year or two of desultory literary work he was appointed to the newly instituted chair of Humanity in the Marischal College. Difficulties arose in the way of his installation, owing to the action of the Presbytery on his refusing to sign unreservedly the Confession of Faith; but these were eventually overcome, and he took up his duties as professor in November 1841. In the following year he married. From the first his professorial lectures were conspicuous for the unconventional enthusiasm with which he endeavoured to revivify the study of the classics; and his growing reputation, added to the attention excited by a translation of Aeschylus which he published in 1850, led to his appointment in 1852 to the professorship of Greek at Edinburgh University, in succession to George Dunbar, a post which he continued to hold for thirty years. He was somewhat erratic in his methods, but his lectures were a triumph of influential personality. A journey to Greece in 1853 prompted his essay On the Living Language of the Greeks, a favorite theme of his, especially in his later years; he adopted for himself a modern Greek pronunciation, and before his death he endowed a travelling scholarship to enable students to learn Greek at Athens. Scottish nationality was another source of enthusiasm with him; and in this connection he displayed real sympathy with highland home life and the grievances of the crofters. The foundation of the Celtic chair at Edinburgh University was mainly due to his efforts. In spite of the many calls upon his time he produced a considerable amount of literary work, usually on classical or Scottish subjects, including some poems and songs of no mean order. Blackie was a Radical and Scottish nationalist in politics, of a fearlessly independent type; possessed of great conversational powers and general versatility, his picturesque eccentricity made him one of the characters of the Edinburgh of the day, and a well-known figure as be went about in his plaid, worn shepherd-wise, over one shoulder and under the other, wearing a broad-brimmed hat, and carrying a big stick. In the 1880s and 1890s, he lectured at Oxford on the pronunciation of Greek, and corresponded on the subject with William Hardie. In May 1893, he gave his last lecture at Oxford, but afterwards admitted defeat, stating: "It is utterly in vain here to talk reasonably in the matter of Latin or Greek pronunciation: they are case-hardened in ignorance, prejudice and pedantry". He died at 9 Douglas Crescent in Edinburgh. He is buried in Dean Cemetery to the north side of the central path in the north section of the original cemetery. His nephew and biographer, Archibald Stodart Walker is buried with him. In 1895 a plaque, designed by Robert Lorimer was erected to his memory in St Giles Cathedral.
