It remained for Greenwood's pupil John Winthrop to be the first to teach Newton at Harvard with adequate mechanical and textual materials. Elected in 1738 to the Hollis professorship formerly held by Greenwood, Winthrop adopted 'sGravesande's _Natural Philosophy_, at which time, Cajori observes, "the teachings of Newton had at last secured a firm footing there."[i-54] The year after his election he secured a copy of the _Principia_ (the third edition, 1726, edited by Dr. Henry Pemberton, friend of Franklin in 1725-1726). According to the astute Ezra Stiles, Winthrop became a "perfect master of Newton's Principia--which cannot be said of many Professors of Philosophy in Europe."[i-55] That he did not allow Newtonianism to draw him to deism may be seen in Stiles's gratification that Winthrop "was a Firm friend to Revelation in opposition to Deism." Stiles "wish[es] the evangelical Doctors of Grace had made a greater figure in his Ideal System of divinity," thus inferring that Winthrop was a rationalist in theology, however orthodox.[i-56] A cursory view of the eighteenth-century pulpit discloses that if the clergy did not become deistic they were not blind to a natural religion, and often employed its arguments to augment scriptural authority. Aware of the writings of Samuel Clarke, Wollaston, Whiston, Cudworth, Butler, Hutcheson,[i-57] Voltaire, and Locke, Mayhew revolts against total depravity[i-58] and the doctrines of election and the Trinity, arraigns himself against authoritarianism and obscurantism, and though he draws upon reason for revelation of God's will, he does not seem to have been latitudinarian in respect to the holy oracles. Although he often wrote ambiguously concerning the nature of Christ, he asserted: "That I ever denied, or treated in a bold or ludicrous manner, the divinity of the Son of God, as revealed in scripture, I absolutely deny."[i-59] He is antagonistic toward the mystical in Calvinism, convinced that "The love of God is a calm and rational thing, the result of thought and consideration."[i-60] His biographer thinks that Mayhew was "the first clergyman in New England who expressly and openly opposed the scholastic doctrine of the trinity."[i-61] Coupling "natural and revealed religion," he does not threaten but he urges that one "ought not to leave the clear light of revelation.... It becomes us to adhere to the holy Scriptures as our only rule of faith and practice, discipline and worship."[i-62] In Mayhew one finds an impotent compromise between Calvinism and the demands of reason, fostered by the Enlightenment. Like Mayhew's, in the main, are the views of Dr. Charles Chauncy, who reconciled the demands of reason and revelation, concluding that "the voice of reason is the voice of God."[i-63] Jason Haven and Jonas Clarke are typical of the orthodox rationalists who were alive to the implications of science, and to such rationalists as Tillotson and Locke.