Although his dialogue is nominally directed only against the Socinians, it is full of valuable remarks on the anti-Trinitarians generally; and he brings out some points more clearly and forcibly than subsequent and more voluminous writers on the subject have done. For example, he meets the old objection that the doctrine of the Trinity is incredible as involving a contradiction, by pointing out that it rests upon the fallacy of arguing from a nature which we know to quite a different nature of which we know little or nothing.[435] The objection that the Christian Trinity was borrowed from the Platonists he turns against the objectors by asking, 'What is become of the master argument of the Socinians that the Trinity is contradictory to common sense and reason?--Yet now they would make it the invention of the principal and most celebrated philosophers, men of the most refined reason.'[436] On the whole this is a very valuable contribution to the apologetic literature on the subject of the Trinity, for though Leslie, like his predecessors, sometimes has recourse to abstruse arguments to explain the 'modes' of the divine presence, yet he is far too acute a controversialist to lay himself open, as Sherlock and South had done, to imputations of heresy on any side; and his general method of treating the question is lucid enough, and full of just such arguments as would be most telling to men of common sense, for whom rather than for profound theologians the treatise was written. About the same time that this treatise was published, there arose what was intended to be a new sect, or, according to the claims of its founders, the revival of a very old one--a return, in fact, to original Christianity. The founder or reviver of this party was William Whiston, a man of great learning, and of a thoroughly straightforward and candid disposition, but withal so eccentric, that it is difficult sometimes to treat his speculations seriously. His character was a strange compound of credulity and scepticism. He was 'inclined to believe true' the legend of Abgarus' epistle to Christ, and Christ's reply. He published a vindication of the Sibylline oracles 'with the genuine oracles themselves.' He had a strong faith in the physical efficacy of anointing the sick with oil. But his great discovery was the genuineness and inestimable value of the Apostolical Constitutions and Canons. He was 'satisfied that they were of equal value with the four Gospels;' nay, 'that they were the most sacred of the canonical books of the New Testament; that polemical controversies would never cease until they were admitted as the standing rule of Christianity.' The learned world generally had pronounced them to be a forgery, but that was easily accounted for. The Constitutions favoured the Eusebian doctrines, and were therefore repudiated of course by those who were interested in maintaining the Athanasian heresy.