The son of Thomas Finlason of Camberwell, Surrey, he entered the Middle Temple on 5 January 1841, and for some years practised as a special pleader under the bar, reporting also for several years, as a member of the parliamentary corps of The Times in the Strangers' Gallery of the House of Commons.
[1] A Roman Catholic convert of 1849, at the hands of Frederick William Faber, Finlason wrote for The Rambler and Dublin Review.
He was a Catholic apologist, defender of John Henry Newman, and opponent of Whig historians.
[2] Although only a "stuff-gown man" (junior barrister), Finlason was appointed one of the masters of the bench of the Middle Temple.
He died on 11 March 1895 at his residence, 12 Campden Hill Road, Kensington, London.