twin brother of Henry Vaughan, was an ordained Anglican minster, and evicted from his living at Llansantffraed in 1650 for misconduct. A disciple of Cornelius Agrippa, he published various treatises on alchemy, magic, and mysticism, including Anima Magia Abscondita: or a Discourse on the Universall Spirit of Nature (1650) and Magia Adamica; or the Antiquity of Magic (1650); Aula Lucis, or the House of Light (1652); and a Preface to a Rosicrucian work, The Fame and Confession of the Fraternity of R.C., Commonly, of the Rosie Cross (1652). Most of his works were published under the pseudonym of ‘Eugenius Philalethes’ (‘Good Truth‐Loving Man’). He engaged in furious controversy with the Platonist Henry More (see Cambridge Platonists), who had attacked his Anthroposophia (1650) as nonsense. After the Restoration, Thomas enjoyed the patronage of Sir Robert Moray, first president of the Royal Society. Moran and Vaughan accompanied the court to Oxford to flee the plague in 1665, and Vaughan died at Albury, according to A. Wood, of mercury poisoning. He was satirized by S. Butler in his ‘Character of a Hermetic Philosopher’, and is said to have suggested some aspects of Ralpho in Hudibras. Swift, in A Tale of a Tub, described him as a writer of the greatest gibberish ‘ever published in any language’.