4to; and ‘Primitive Heresie Revived in the Faith and Practice of the People called Quakers,’ with ‘A Friendly Expostulation with Wm. Penn upon account of his Primitive Christianity,’ London, 1698, 4to (reprinted with the preceding tract in ‘Five Discourses by the Author of “The Snake in the Grass,”’ London, 1700, 8vo). He also published a new edition of ‘The Snake in the Grass,’ largely rewritten, with a preface on Madame Bourignon, whose enthusiasm he sought to connect with quakerism, and a supplement in answer to Whitehead's ‘Antidote against the Venome of the Snake in the Grass,’ &c., London, 1697, 8vo. A third edition, 1698, 8vo, elicited a dignified reply from Joseph Wyeth, ‘Anguis Flagellatus; or a Switch for the Snake,’ London, 1699, 8vo. Leslie, however, had the last word, and a very long and strong one, in ‘A Defence of a Book intituled “The Snake in the Grass,”’ London, 1700, 8vo, and ‘A Reply to a Book entituled “Anguis Flagellatus” … shewing that the Quakers are plainly self-condemn'd in this their last Answer. And therefore it is to be hop'd that this will put an end to that controversy,’ London, 1702, 8vo.
All this while Leslie had been skirmishing vigorously in defence of the sacraments. In 1697 he published ‘A Discourse proving the Divine Institution of Water Baptism,’ London, 4to. In the preface to this tract Leslie boasts that only a year's study of it had sufficed to convert an inveterate male quaker. It was followed by ‘A Discourse shewing who they are that are now qualify'd to administer Baptism and the Lord's Supper. Wherein the cause of Episcopacy is briefly treated,’ London, 1698, 4to. Both tracts were reprinted in ‘Five Discourses by the Author of “The Snake in the Grass,”’ London, 1700, 8vo, and the former separately in 1707, London, 4to. Leslie further discussed the matter in ‘A Religious Conference between a Minister and Parishioner concerning the Practice of our Orthodox Church of England in Baptism and Confirmation. With a Vindication of the Lawfulness of Godfathers and Godmothers and of the Sacred Order of Bishops,’ London, 1698, 8vo; and ‘The Case of Sureties in Baptism. In which is shewn that schismaticks ought not to be admitted as Godfathers and Godmothers in the Ministration of the Holy Sacrament,’ London, 1701, 4to. The following miscellanea also belong to the same period: ‘The History of Sin and Heresie attempted,’ London, 1698, 4to; ‘A Parallel between the Faith and Doctrine of the present Quakers and that of the chief Hereticks in all ages of the Church,’ London, 1700, 4to; ‘An Essay concerning the Divine Right of Tythes,’ London, 1700; ‘The Present State of Quakerism in England. Upon occasion of the relapse of Sam. Crisp [one of Leslie's converts] to Quakerism,’ London, 1701.
Nor was Leslie so preoccupied with the quaker as to neglect the deist and the Jew. To a lady friend, ‘who had been staggered with the arguments of deism even to distraction,’ he wrote a letter containing a brief summary of the evidences of Christianity, as he conceived them, ‘prevailed with her to copy it in her own hand,’ and thus established her in the faith. This argument he published, retaining the epistolary form, but substituting ‘sir’ for ‘madam,’ as ‘A Short and Easie Method with the Deists, wherein the truth of the Christian Religion is demonstrated by such rules as stand upon the conviction of our outward Senses, and which are incompatible with the Fabulous Histories of the Heathen Deities, the Delusions of Mahomet, or any other Imposture whatsoever. In a Letter to a Friend,’ London, 1698, 8vo. That such was the origin of this celebrated argument Leslie himself states (Vindication, § 1). It has been conjectured that the lady was a sister of Henry Hyde, second earl of Clarendon, Lady Frances Keightley, who went into retreat at Glaslough in 1686, in which case the first draft was probably made while Leslie was still in Ireland; but of this there is no proof [see under Keightley, Thomas, 1650?–1719]. Oddly enough, Leslie's own account has been set aside in favour of a tradition which makes the Duke of Leeds the person for whose benefit Leslie wrote (see A Short and Easy Method with the Deists, &c., ed. Jones, London, 1799, p. viii, and A Letter to a Noble Duke on the Incontrovertible Truth of Christianity, 2nd edition, London, 1808, p. xiii). A companion treatise against the Jews, entitled ‘A Short and Easie Method with the Jews. Wherein the certainty of the Christian Religion is demonstrated by infallible proof from the four rules made use of against the Deists,’ dated, with dramatic propriety, on Good Friday, appeared the same year, and both were reprinted in one volume, London, 1699, 12mo. The ‘Method with the Deists’ is nothing if not historical. The miracles are supposed to vouch for the doctrine, and be in their turn vouched for by conformity to four rules of historical evidence, such conformity being assumed sufficient to prove the truth of any alleged ‘matter of fact,’ however extraordinary. The rules to which the miraculous narratives in the scriptures in Leslie's view conform are: ‘1. That the matter of fact be such as that men's outward senses, their eyes
