A man of notable intellectual power, he exercised an influence remarkable especially as he died in his 36th year. He was one of the most formidable controversialists of a highly controversial age. His best known work is ''Aaron's Rod Blossoming'', a defense of the ecclesiastical claims of the high
Presbyterian party. While with the Earl of Cassillis he wrote his first work,
A Dispute against the English Popish Ceremonies obtruded upon the Church of Scotland, which, published shortly after the "
Jenny Geddes" incident (but without the author's name) in the summer of 1637, attracted considerable attention. Within a few months it had been found by the Privy Council to be so damaging that by their orders all available copies were called in and burnt. His principal publications were controversial and chiefly against
Erastianism: • Three sermons against
Thomas Coleman; • A Sermon before the House of Lords (27 August 1645), on Matt. iii. 2, Nihil Respondem and Male Audis; • Aaron's Rod Blossoming, or the Divine Ordinance of Church-government vindicated (1646), which is regarded as an able statement of the case for an exclusive spiritual jurisdiction in the church; • One Hundred and Eleven Propositions concerning the Ministry and Government of the Church (Edinburgh, 1647). The following were posthumously published by his brother: • A Treatise of Miscellany Questions (1649); • The Ark of the New Testament (2 vols., 1661–1667); • Notes of Debates and Proceedings of the Assembly of Divines at Westminster, from February 1644 to January 1645. See also
Works, with memoir, published by
William Maxwell Hetherington (Edinburgh, 1843–1846). • An assertion of the government of the Church of Scotland, in the points of ruling-elders, and of the authority of presbyteries and synods : with a postscript in answer to a treatise lately published against presbyterial government .. (1641) • Useful Case of Conscience Discussed and Resolved: Concerning Associations and Confederacies ... (1649) • The Works of Mr. George Gillespie (Vol. 1 of 2) • Testimony-bearing exemplified : a collection. Containing, I. Gillepsie against association with malignants; together with the causes of God's wrath, agreed upon by the General assembly of the Church of Scotland, met at Edinburgh, October 1651. II. The informatory vindication; to which is subjoined, a collection of excellent laws, (or Eschol grapes) in favours of our covenanted reformation .. (1791) • A Dispute against the English Popish Ceremonies obtruded upon the Church of Scotland (1637; another edition, 1844) • An Assertion of the Church Covenant of Scotland (1641) • Dialogue between a Civilian and a Divine, concerning the Present Condition of the Church of England (London, 1644) • A Recrimination in Defence of Presbyterianism (London, 1644) • Nihil Respondes (London, 1645) • The True Resolution of a Present Controversy concerning Liberty of Conscience (London, 1645) • Wholesome Severity reconciled, with Christian Liberty (London, 1645) • Aaron's Rod Blossoming (London, 1646 ) • Male Audis, an Answer to Coleman's Male Dicis (London, 1646) • A Treatise of Miscellany Questions (Edinburgh, 1649) • A Useful Case of Conscience Discussed (Edinburgh, 1649) • Works, with memoir by W. M. Hetherington, LL.D., 2 vols. (Edinburgh, 1843-6) • Notes of Debates and Proceedings of the Assembly of Divines, edited by David Meek (Edinburgh, 1846). ==References==