1741. Middleton had three thousand subscribers, and gained a considerable sum, which, as he says, would enable him to provide for two nieces of about eight years old, left to him by ‘an unfortunate brother who had nothing else to leave’ (Works, i. 397). He also bought from the profits a small estate at Hildersham, six miles from Cambridge, where he turned a ‘rude farm’ into an ‘elegant habitation,’ and spent his summers. He was still living at Cambridge, where he met his friends every night at the coffee-house. Gray, who came into residence in 1742, found Middleton's house the only agreeable place for conversation in Cambridge. His house adjoined Caius College, and looked over the senate-house yard. Cole also speaks of his great charm in society.
Middleton returned to his theological controversies by his writings upon the miraculous powers attributed to the Christian church. He published an ‘Introductory Discourse’ in 1747, followed up by a fuller treatise at the end of 1748. The book denied the credibility of the stories of miracles in periods subsequent to the first age of the church, attacked the character of the narrators, and explained the origin of the narratives by the general credulity of the times in which they arose. The book produced a lively controversy. Hume found that it had eclipsed the volume of essays (published in April 1748), which included his own argument against the credibility of miracles. Gibbon's temporary conversion to catholicism soon afterwards was chiefly due to a perusal of Middleton. The continuity of the claim to miraculous power seemed to him to confirm the later, instead of disproving the earlier stories. Middleton was generally thought to favour the inverse conclusion, although he professed to deny the applicability of his arguments to the first age of the church. The very natural doubts of his sincerity were confirmed by the last volume which he published, an examination of Sherlock's discourses on prophecy (1749–50). Middleton's main position as to the nature of the argument from prophecy might pass for orthodox, but he again attacked the Mosaic account of the fall. Sherlock's book was first published in 1725, in answer to the deist Anthony Collins [q.v.] . Middleton declares that he had never read it until he wrote against it, although it had then been a popular treatise for many years. The bookseller Whiston reported, on the authority of Sherlock, that Middleton professed at least to have read the book when presented by its author on the first publication (see Chalmers, Biog. Dict.) Middleton, however, is said to have had a personal cause of offence. In 1737 he tried to obtain the mastership of the Charterhouse. He says at the time (Misc. Works, i. 390) that Walpole was in his favour, but that the Duke of Newcastle had obtained the appointment for a friend. Walpole, however, afterwards informed him that his failure had really been caused by Sherlock's declaration that the bishops would be offended by Middleton's appointment. Cole says that he heard this from Middleton himself, and the story is repeated in Bishop Newton's autobiography. Warburton says to Hurd (11 July 1750, Letters of an Eminent Prelate, p. 59) that Middleton had been prejudiced against religion ‘by the pretended injuries of some churchmen.’ Such imputations generally deserve little attention, but it must be admitted that, whatever his personal motives, Middleton was probably one of the few divines who can be fairly accused of conscious insincerity. In a letter to Lord Hervey (see Nichols, Anecdotes, v. 421) he says that he would like to have some amends (in the shape of preferment) for that ‘ugly assent and consent, which no man of sense can approve of.’ Except Coveney and the rectory of Hascombe, Surrey, worth 50l. a year, to which he was presented by Sir John Frederick in March 1746–7 (ib. v. 419, 700), he held no preferment, and is said to have observed that as he had not been trusted (with a bishopric) he was ‘at liberty to speak his mind’ (ib. p. 421). His letters to Hervey show that he was much aggrieved at not obtaining preferment. Warburton said (ib. p. 648) that Middleton only went so far as to ‘suspend his belief’ in regard to revelation (see Middleton's Letters to Warburton in Misc. Works, i. 374, 383, 394, which suggested this statement). However his position may be judged from a moral point of view, there can be no doubt that he was far too able a man to be blind to the tendency of his arguments. Not long before his death Middleton married a third wife, Anne, daughter of John Powell of Boughrood, near Radnor. She had lived with Mrs. Trenchard, widow of John Trenchard [q. v.], afterwards married to Thomas Gordon (d. 1750) [q. v.] His health was breaking, and while he was preparing a general answer to the critics of the ‘Free Enquiry,’ he died at Hildersham, ‘of a slow hectic fever and disorder in his liver,’ on 28 July 1750. He was engaged in a lawsuit with a builder at the time of his death (Walpole, Letters, ii. 237; Letters of an Eminent Prelate, p. 54). Middleton left behind him several manuscripts, some of which appeared in the posthumous collection of his ‘Miscellaneous Works.’ His papers were left by his widow to Dr. Heberden. Heberden is said to have