Molyneux (Molyneaux), William (1656–98), scientist and political writer, was born in Dublin, 17 April 1656, eldest surviving son of Samuel Molyneux (1616–93), master gunner of Ireland and his wife, Margaret, daughter and co-heiress of William Dowdall, merchant of Dublin. His great-grandfather, Thomas Molyneux (qv), had left the Pale of Calais in 1558, and settled in Dublin in the later 1570s as a protégé of Archbishop Adam Loftus (qv), eventually becoming chancellor of the Irish exchequer. In the intervening decades the Molyneuxs established marriage connections with the Usshers and other prominent Dublin families.
Early life and scientific interests
William Molyneux was educated at St Patrick's cathedral grammar school, and entered Trinity College Dublin (TCD) as a fellow commoner in April 1671. He graduated Bachelor of Arts in February 1674, becoming Master of Arts in 1692; his college contemporaries included the future provost St George Ashe (qv) and the politician and writer Robert (later 1st Viscount) Molesworth (qv). He pursued legal studies at the Middle Temple in London from June 1675 to June 1678, and on his return was called to the Dublin bar. Although Molyneux claimed in his 1694 autobiography to have been an unenthusiastic law student and reluctant practitioner, he was an assiduous compiler of legal commonplace-books and amassed an extensive collection of law books.
On 19 September 1678 Molyneux married Lucy, youngest daughter of the Irish attorney general Sir William Domvile (qv). Her loss of sight in early 1679 drew him to the study of optics and eye diseases, which soon broadened into a more general interest in the new science. During the winter of 1679–80 he translated parts of John Donne's Biathanatos and Galileo's Discorsi … intorno a due nuove scienze, together with the whole of Descartes's Meditationes de prima philosophia, the last of which was published in London in April 1680. In September 1681 Molyneux initiated a correspondence with the astronomer John Flamsteed which, thanks to the latter's patient encouragement, helped to transform him over the next ten years from an enthusiastic amateur into a serious inquirer into nature. In 1682 he assumed responsibility for organising the Irish section of Moses Pitt's projected Atlas. The collapse of the scheme through lack of funds the following year led Molyneux to destroy his own work for the project, though a number of other county surveys survive among his papers in TCD. In October 1683, helped by his brother Thomas Molyneux (qv), he started Ireland's first scientific society in imitation of the Royal Society of London. In January 1684 the group was reorganised along more formal lines as the Dublin Society for the Improving of Natural Knowledge, Mathematics and Mechanics (later known as the Dublin Philosophical Society), Sir William Petty (qv) being the first president and Molyneux secretary. With fourteen original members comprising clergymen, physicians, and landowners, the Dublin Society embarked on four years of fruitful activity and expansion till the disruption of the Tyrconnell regime forced their suspension in 1687. More than two dozen of the members’ papers from this period, including ten by Molyneux, were subsequently published in the Philosophical Transactions of the Royal Society.
Scientific publications and philosophical studies
In October 1684 Molyneux paid £250 to the current holder, William Robinson (qv), for a half share in the post of surveyor-general of fortifications and buildings, with a salary of £300 p.a. The following year he was granted £100 to undertake an official visit to the continent to view fortifications, later joining his brother Thomas, who was studying medicine at Leiden, on a tour of the Netherlands, the Rhineland, and France. The brothers met notable scientists such as Christian Huygens, the microscopist Leeuwenhoek at Delft, and the astronomer Cassini in Paris. On his way back through London, Molyneux made contact with Flamsteed, together with other scientists such as Edmund Halley and Robert Hooke, and after his return to Dublin was admitted to the Royal Society in September 1685. His first independent publication, Sciothericum telescopium, describing the construction and uses of an astronomical instrument which he had devised for time-keeping and other calculations, appeared in Dublin the following year. In early 1687 he and Robinson were deprived of the surveryorship by the lord deputy, the earl of Tyrconnell (qv), though, after his partner's departure to England, Molyneux carried out extensive building work at Dublin castle, presumably to Robinson's designs. Payment for this helped to maintain him, his wife and son, and his brother in Chester when they too fled from the Tyrconnell regime in February 1689.
While at Chester Molyneux wrote his most important scientific work, Dioptrica nova, a lengthy geometrical treatise on optics, which was published in late 1691. The work consisted of two parts: the first described the mathematical properties of lenses and their use in telescopes and microscopes, while the second was more anecdotal. Dioptrica nova could not have been written without the help of Flamsteed and particularly Halley, who took on the responsibility of seeing it through the press. Nonetheless, the book was a significant contribution to the subject in English, and was important for the background it provided to George Berkeley (qv) for his New theory of vision (1709). Its appearance brought about the end of Molyneux's friendship with Flamsteed, who protested (with some justification) at his failure to acknowledge his intellectual debts. However, a fulsome reference to John Locke in the work's dedication to the Royal Society, followed by a presentation copy, led to the start of a correspondence, published in Some familiar letters between Mr Locke and several of his friends (1708), which was to develop into Molyneux's most celebrated friendship.
Following the Williamite taking of Dublin in July 1690, Molyneux returned home; shortly afterwards his wife died leaving him to raise their sole surviving child, Samuel (qv), who became a distinguished astronomer and secretary to the prince of Wales (later George II). Samuel's upbringing was conducted in accordance with Locke's Some thoughts concerning education (1693), and educational matters figured extensively in Molyneux's correspondence with Locke. In 1692 Molyneux persuaded his friend St George Ashe, now provost of TCD, to adopt Locke's An essay concerning human understanding as a text for graduate bachelors of arts at Trinity, thus giving the first academic recognition of Locke's work. Molyneux made important contributions to the second edition of the Essay (1694) in persuading Locke to add a new chapter on identity and greatly to extend his treatment of ‘power’, as well as introducing the perceptual problem later known as the ‘Molyneux problem’. This dealt with the question whether a blind man, on becoming able to see, would be able to distinguish by sight alone the difference between a sphere and a cube, which he had previously known through the medium of touch. Locke handsomely acknowledged his debt for it to ‘the worthy Mr Molyneux whom I am proud to be able to call my friend’ (Essay, bk ii, chap. ix, section 8). The Molyneux problem received attention from prominent philosophers and scientists over the next three centuries, and is still discussed. Further suggestions from Molyneux were embodied in the third edition of Locke's Essay in 1697, and he was instrumental in recruiting Ezekiel Burridge to translate the work into Latin.
Once back in Dublin, Molyneux was appointed to the commission for stating army accounts in Ireland, with a salary of £500 p.a., which was still being paid in October 1695. Among his fellow commissioners was William Robinson, with whom he once more shared the post of surveyor general, though now as an entirely inactive partner. He also served from November 1692 to May 1693 as a commissioner for assessing wartime losses to government stores and forfeited goods, at a salary of £400 p.a. Molyneux refused, however, to serve on the commission for forfeited estates, claiming that association with the other commissioners would damage his reputation. In 1692 he was elected second representative for Dublin University in the parliament that sat for less than a month in October–November, an indication of official favour as the government controlled the constituency. The university awarded him a Doctor of Laws degree for his services the following year, and reelected him as their representative in 1695. From the start Molyneux was an active member, serving on important committees and compiling an elaborate index of precedents to facilitate his activities. Although he played a leading role on the committee established to investigate charges against the lord chancellor, Sir Charles Porter (qv), in the 1695 session, the latter subsequently recommended him for appointment as a master in chancery, a potentially lucrative position which also involved liaison between the two houses during meetings of parliament. In the 1697 session he was active in supporting the new lord chancellor, John Methuen (qv), to whom he had been recommended by Locke.
Succession to the family estates in Armagh, Limerick, and Kildare following his father's death in 1693 brought him an increased income (somewhat reduced by war damage), but Molyneux apparently maintained his legal practice up till his death in 1698. On Methuen's departure to the English parliament in December 1697, he was one of the commission who acted as chancery judges in his absence, though not (as has sometimes been asserted) a commissioner for the great seal. He played a smaller role in the revived Dublin Philosophical Society of 1693–7, which focused on technology and Irish antiquities rather than the more overtly scientific interests of the 1680s.
The case of Ireland
From 1696 Molyneux became drawn into the conflict developing between England and Ireland over the competition from Irish woollen exports through privately advising Locke, who was by now a member of the board of trade, on how best to foster the linen industry in Ireland. In the autumn of 1697 he assisted William King (qv), bishop of Derry, to establish precedents for his successful appeal to the Irish house of lords against the Irish Society over a dispute relating to lands and fishery rights near Londonderry. At the beginning of 1698 commercial jealousy broadened into political and constitutional conflict when the Irish Society appealed to the English house of lords against the right of the Irish lords to hear chancery appeals. Legislation was threatened against Irish woollen exports, and a pamphlet war erupted which led to the publication of Molyneux's The case of Ireland's being bound by acts of parliament in England, stated, dedicated to King William (qv), in April 1698. This work, perhaps written in answer to an anonymous pamphlet entitled A letter from a gentleman … in reference to the votes of the 14th instant, said to be by John Toland (qv), ensured Molyneux's reputation as a pioneer Irish patriot. Through a series of nine reprints to 1782, The case deeply influenced Irish protestant attitudes to England throughout the eighteenth century, and also received attention from the colonists in the run up to the American war of independence.
Molyneux asserted that Ireland was an independent kingdom, subject to the king but not to the parliament of England. Its origin lay in the voluntary submission of the Irish princes to Henry II (qv), who in turn granted them English laws and customs, along with the right to hold parliaments. Ireland's constitution rested, therefore, on consent and not on conquest, as English writers claimed. Since the reign of Henry III (1225), English statutes had been reenacted by the Irish parliament before becoming operative in Ireland, a requirement reaffirmed by Poynings’ parliament in 1494. Only with the Adventurers’ Act of 1642, providing for the suppression of the 1641 rebellion, did the English parliament start legislating directly for Ireland, a practice continued after the restoration. Precedents of such recent standing could carry little weight against a constitution established for more than 500 years. Molyneux attached particular importance to Poynings’ law in providing the fundamental statutory link between the two kingdoms, while excluding the English parliament from any role in the law-making process. Minor objections refuted included the assertion that the kingdom of Ireland was a colony similar to England's possessions in America, and the claim that the English parliament had somehow or another ‘purchased’ Ireland by paying for the Jacobite war. Opinion is still divided as to whether Molyneux's apparent call for legislative union with England, described as ‘a happiness we can hardly expect’, was seriously intended or merely a rhetorical device.
In preparing the pamphlet Molyneux drew extensively (though without acknowledgement) on two mid-seventeenth-century critiques of the English parliament's claim to legislate for Ireland, the first written by his father-in-law, Sir William Domvile, in 1660, and the second dating from 1644 attributed to the royalist lord chancellor Sir Richard Bolton (qv). The crucial evidence for Henry II's granting a parliament to Ireland was adduced from the Irish Modus tenendi parliamenta, recently published by Molyneux's brother-in-law Bishop Anthony Dopping (qv), while frequent reference was made to seventeenth-century English legal writers such as Prynne, Selden, Petyt, and above all Sir Edward Coke. Molyneux acknowledged an extensive debt to Locke's Two treatises of government for exposing the inadequacy of conquest as the basis for government, and subsequently implicitly extended Locke's universal right to consent to the laws by which one was governed to assert that no nation had the right to dominate another. Unbeknown to Molyneux, Locke was far from pleased at being publicly associated with the hitherto anonymous Two treatises of government and with the end to which his arguments were put.
In the short term the publication of The case caused great difficulty not only for Molyneux, but for Irish interests in England generally. Although Molyneux had tried to temper his arguments to English susceptibilities, he was strangely unaware how offensive remarks such as the comparison between the destruction of the Irish constitution and the revocation of the edict of Nantes would appear. An inquiry was held by the English house of commons, in which, thanks to the efforts of Lord Chancellor Methuen and his old friend Robert Molesworth, Molyneux was lucky enough to escape personal condemnation, though his book was declared to be ‘of dangerous Consequence to the Crown and People of England’ (Journals of the House of Commons, xii, 327). The story that the English parliament went on to condemn The case of Ireland to be burnt by the public hangman did not make its appearance till the end of the second decade of the eighteenth century. But from its first dissemination in print in a letter to the London Daily Journal of 8 February 1729, signed ‘Philo-Britannus’ (attacking Swift's Intelligencer, no. 15), it enormously enhanced the reputation of both Molyneux and his book. Three replies to The case were published by English whigs in 1698, and two further responses by tories in 1698. Even in Ireland, however, the book had few immediate admirers.
Death and legacy
Once the English parliamentary session ended in July 1698 Molyneux made a prolonged visit to Locke in England, which proved a great satisfaction to the two friends; he also sat for a portrait by Kneller, at Locke's request. Shortly after his return Molyneux died at his home near Ormond Gate in Dublin on 11 October 1698 of a chronic kidney complaint; he was buried in St Audoen's church. His extensive library passed to his son, Samuel, and was mostly sold in 1730, following the latter's death without issue two years earlier. Thereafter the Molyneux family estates passed to William's brother Thomas, by then Ireland's first medical baronet. Thomas's great-grandson Sir Capel Molyneux was an ardent champion of William Molyneux's reputation and was responsible for the private printing of his 1694 autobiography in 1803.
There is a half-length portrait in oils on canvas by Sir Godfrey Kneller, 1698, in the National Portrait Gallery, London; a half-length portrait, engraved by Philip Simms, appears as the frontispiece to the 1725 edition of The case of Ireland … stated; and Robert Home's full-length portrait in oils on canvas, 1783, in which Molyneux is one of a series of distinguished figures associated with TCD, was commissioned for and now hangs in the public theatre of the college. The main collections of Molyneux's papers are in the library of TCD (MSS 881–893) and in the Pitt Collection, Southampton Public Library.