7 April 1656|
|Died||11 October 1698
|Occupation||Member of Parliament|
|Known for||Dublin Philosophical Society|
|Awards||Fellow of the Royal Society|
He was born in Dublin to Samuel Molyneux (1616–1693), lawyer and landowner (whose grandfather had come to Dublin from Calais), and his wife, Anne, née Dowdall. The second of five children, William Molyneux came from a relatively prosperous Anglican background, with the family holding large estates inherited from the Dowdall's in Ballymulvey, (Mulvey being an Anglicization of Molyneux) near Ballymahon in the County of Longford. He was close to his brother Thomas, with whom he later shared philosophical interests. In 1671 Molyneux started at Trinity College, Dublin where he became an avid reader of the leading figures of the Scientific Revolution. After attaining a Bachelor of Arts there, Molyneux was sent to study law in the Middle Temple, London from 1675 to 1678. In 1678 he married Lucy Domville (?–1691), the youngest daughter of Sir Wiliam Domville the Attorney-General for Ireland. His wife became ill, which led to blindness, after their marriage and died young. Of their 3 children, only Samuel Molyneux (1689–1728) lived past childhood. Samuel went on to become an astronomer and politician who worked with his father on various scientific endeavours.
Career & Publications
Due to his inheritance, Molyneux was financially independent.  Nonetheless, he held a number of official positions throughout his life. He was appointed Joint Surveyor General of the King's buildings and works in Ireland in 1684. He represented Dublin University in Parliament from 1692 until his death. He had also served as a commissioner of forfeited estates in 1693, resigning a few months later due to ill health.
Meanwhile, Molyneux was responsible for a number of publications reflecting his diverse interests. His first book was editing and translating into English the work of René Descartes which was published in London, 1680 as Six Metaphysical Meditations, Wherein it is Proved that there is a God.... In 1682 Molyneux collaborated with Roderic O'Flaherty to collect material for Moses Pitt's Atlas. In 1685, Pitt's financial crisis lead to cancellation of the project but much valuable early Irish history had been collected. Molyneux struck a friendship with O'Flaherty and assisted when the latter's treatise Ogygia was published in London.
Meanwhile, in October 1683 he founded the Dublin Philosophical Society along the lines of the Royal Society (of which Molyneux became a fellow in 1685), and became its first Secretary. He was active in the proceedings of the society—recording weather data, calculating eclipses and demonstrating instruments and experiments.
Molyneux also published several papers in Philosophical Transactions, as well as papers on optics, natural philosophy, and miscellaneous topics. Perhaps his best known scientific work was Dioptrica Nova, A treatise of dioptricks in two parts, wherein the various effects and appearances of spherick glasses, both convex and concave, single and combined, in telescopes and microscopes, together with their usefulness in many concerns of humane life, are explained, published in London 1692.
Early in 1698, Molyneux published The Case of Ireland's being Bound by Acts of Parliament in England, Stated. This controversial work—through application of historical and legal precedent—dealt with contentious constitutional issues that had emerged in the latter years of the seventeenth century as a result of attempts on the part of the English Parliament to pass laws that would suppress the Irish woolen trade. It also dealt with the disputed appellate jurisdiction of the Irish House of Lords. Molyneux's arguments reflected those made in an unpublished piece written by his father-in-law Sir William Domville, entitled A Disquisition Touching That Great Question Whether an Act of Parliament Made in England Shall Bind the Kingdom and People of Ireland Without Their Allowance and Acceptance of Such Act in the Kingdom of Ireland.
Following a debate in the English House of Commons, it was resolved that Molyneux's publication was 'of dangerous consequence to the crown and people of England by denying the authority of the king and parliament of England to bind the kingdom and people of Ireland'. Despite condemnation in England, Molyneux was not punished but his work was condemned as seditious and was ceremonially burned at Tyburn by the public hangman. His arguments remained topical in Ireland as constitutional issues arose throughout the eighteenth century, and formed part of Swift's argument in Drapier's Letters. The tract also gained attention in the American colonies as they moved towards independence. Although The Case of Ireland, Stated was later associated with independence movements—both in Ireland and America—as one historian points out, 'Molyneux's constitutional arguments can easily be misinterpreted' and he was 'in no sense a separatist'.
Molyneux, who died in Dublin on 11 October 1698, also proposed the philosophical question that has since become known as Molyneux's Problem, which Locke discussed in later editions of the Essay. The problem of the blind man who gains sight, which he proposed to Locke, remains a topic that is discussed even in our day. The University Philosophical Society of Trinity College, Dublin views itself as the successor of the Dublin Philosophical Society, and thus recognises Molyneux as its founder and first president.
- Dublin Historical Record, 1960
- Science and Its Times via "William Molyneux Summary". Retrieved 24 July 2007.
- James G. O'Hara, 'Molyneux, William (1656–1698)', Oxford Dictionary of National Biography, Oxford University Press, Sept 2004; online edn, Jan 2008 accessed 4 November 2008
- James G. O'Hara, 'Molyneux, William (1656–1698)', Oxford Dictionary of National Biography, Oxford University Press, Sept 2004; online edn, Jan 2008
- Hoppen, K. Theodore (1963). "The Royal Society and Ireland. William Molyneux, F.R.S. (1656–1698)". Notes and Records of the Royal Society of London 18 (2): 125–135. doi:10.1098/rsnr.1963.0016. JSTOR 531268
- Patrick Kelly. 'Sir William Domville, A Disquisition Touching That Great Question...', Analecta Hibernica, no. 40 (2007): 19–69.
- James G. O'Hara, 'Molyneux, William (1656–1698)', Oxford Dictionary of National Biography, Oxford University Press, Sept 2004; online edn, Jan 2008 accessed 29 Feb 2008
- Ferguson, Oliver W. Jonathan Swift and Ireland p. 119
- David Dickson, New Foundations: Ireland 1660–1800 (Dublin, 2000), 50.
|Wikimedia Commons has media related to William Molyneux.|
- Europa Biography
- O'Connor, John J.; Robertson, Edmund F., "William Molyneux", MacTutor History of Mathematics archive, University of St Andrews.
- FromThe Online Library of LibertyThe Case of Ireland being bound by Acts of Parliament in England, Stated 
|Parliament of Ireland|
|Member of Parliament for Dublin University
Served alongside: Sir Cyril Wynche 1692–1695
Richard Aldworth 1695–1698
|Surveyor General of Ireland
Served alongside: William Robinson
Thomas de Burgh