The present paper was prepared because the career of Hugh, Lord Willoughby—President of the Society from 1754 until his death in 1765—had been largely overlooked by historians, and denied even the briefest of general summaries. Yet it was a career characterized by industry, by versatility, by probity; and if in political areas it was impaired by Willoughby's diffidence, so that the opportunities arising from his own undoubted abilities and from Chancellor Hardwicke's patronage were scarcely ever taken up, it seems to have reached much more complete fruition intellectually in this Nonconformist peer's association with the Society of Antiquaries, the British Museum, the Royal Society, the Society of Arts, and the Warrington Academy. Most particularly it epitomizes the close involvement of Dissenters in the eighteenth-century Enlightenment.