Ashe, St George (1658–1718), scholar and Church of Ireland bishop, was born in Co. Roscommon, in 1658, the second of three sons of Thomas Ashe, a landowner of English extraction, and Jane White of Richerstown. He entered TCD in 1671, graduating BA in 1676. Three years later, he received his MA and was elected a fellow of the college. His students included William Congreve (qv) and Jonathan Swift (qv); the latter became a close friend, and was a regular visitor to the home of Ashe's younger brother Dillon, vicar of Finglas. Ashe assisted William Molyneux (qv) in founding the Dublin Philosophical Society in 1684, intended as an Irish version of the London Royal Society (of which he became a member in 1686). Ashe was one of the most committed and active members of the Dublin Philosophical Society, reading at least 28 papers at meetings between 1683 and 1687, and conducting a range of public experiments, some of which concerned freezing. In 1685 he succeeded Molyneux as secretary of the Society, and Miles Symner (qv) as Donegal lecturer and professor of mathematics in 1686, a position that required him to deliver three lectures during each week of term. In the mid 1680s he was also involved in the construction of an observatory at TCD.
He graduated BD in 1687, but his burgeoning scientific career was disrupted by the political instability of the late 1680s, and during the Williamite war (1689–91) he lived abroad, working as chaplain to Lord Paget, English ambassador to Vienna. He returned to Ireland in 1692, where he graduated DD and was appointed provost of TCD. Introduced by Molyneux to the work of John Locke, he immediately incorporated Locke's Essay concerning human understanding (1690) into the college syllabus. In 1702 he was appointed vice-chancellor of Dublin University. Adjacent to his intellectual interests, he pursued a successful career in the church, being bishop successively of Cloyne (1695), Clogher (1697), and Derry (1717), and publishing several of his sermons. He married Jane, daughter of Sir George St. George of Dunway; they had a son St George, and a daughter, Elizabeth, who married Sir Ralph Gore (qv), chancellor of the exchequer. Ashe died 27 February 1718 in Dublin, and was buried in Christ Church cathedral. His friend Joseph Addison (qv) described him as an ‘excellent man’ who ‘has scarce left behind him his equal in humanity, agreeable conversation, and all kinds of learning’ (Graham, 400).
Collections of Ashe's papers are held in the Bodleian Library, Oxford, the Royal Society, London, and TCD. A portrait attributed to Hugh Howard (qv) is in TCD.