King's College was then famous for the study of music; Preston chose 'the noblest but hardest instrument, the lute', but made little progress.
[1] About 1611, the year in which he commenced MA, he heard a sermon at St Mary's from John Cotton, then fellow of Emmanuel, which opened to him a new career.
He returned to his rooms, somewhat mortified by his reception, when Preston knocked at his door, and that close religious friendship began which permanently influenced the lives of both.
Preston now gave himself to the study of scholastic divinity; Aquinas seems to have been his favourite ; he thoroughly mastered also Duns Scotus and William of Ockham.
[1] His biographer tells a curious story of his activity in securing the election (1614) of John Davenant as master of Queens' in succession to Tyndal.
George Montaigne, afterwards Archbishop of York, had his eye on this preferment; but immediately on Tyndal's death Preston rode post-haste to London, reaching Whitehall before day-break.
Here he made interest with Robert Carr, 1st Earl of Somerset, with a view to secure court sanction for the choice of Davenant.
He was chosen by Samuel Harsnett, the vice-chancellor, as 'answerer' in the philosophy act, but this place was successfully claimed by Matthew Wren, and Preston took the post of first opponent.
James was delighted with his argument (which Granger thinks Preston borrowed from a well-known passage in Montaigne's Essays), and introduced a dog story of his own.
But Preston had by this time given up his early ambition; though he said little of his purpose, his mind was set on the ministry, and he was reading modern divinity, especially Calvin.
His strictness greatly increased his reputation as a tutor with puritan parents; 'he was,' says Fuller, 'the greatest pulpit-monger in England in man's memory.
A dispute with Newcome at St. Botolph's delayed the afternoon service; to make room for the sermon, common prayer was for once omitted.
At the suggestion of Lancelot Andrewes, then Bishop of Ely, Preston was directed to declare his judgment regarding forms of prayer in a sermon at St. Botolph's.
James highly approved his argument against the Arminians; he would have shown him less favour had he known that Preston was the author of a paper against the Spanish match, circulated with much secrecy among members of the House of Lords.
After all he had been outwitted, for Williams, the lord keeper, suspecting some puritan plot, had set a spy on his movements, who sent weekly intelligence of his doings.
[1] In February 1622 John Donne resigned the preachership at Lincoln's Inn, and the benchers elected Preston as his successor.
He had outlived his influential friends, and the fellows thought that to secure Preston's interest with Buckingham would be to the advantage of their college.
In particular they wanted a modification of the statutes, which enjoined continuous residence, so cutting them off from chaplaincies and lectureships, and at the same time compelled them to vacate at the standing of DD, whether otherwise provided or not.
Accordingly Chaderton resigned on 25 September; contrary to statute, the vacancy was not announced, on the plea that all the fellows were in residence; the election took place on 2 October with locked gates, and nothing was known of it at Queens' until Preston was sent for to be admitted as master of Emmanuel.
His ingenuity found out evasions to which the fellows consented; the statutes condoned absence in case of 'violent detention ' and of 'college business'; a 'moral violence ' was held to satisfy the former condition, and a suit at law about a college living, which lasted some years, formed a colourable pretext for alleging college business.
He exerted influence on behalf of his puritan friends, obtaining a general preaching license (20 June 1625) for Arthur Hildersam.
Preston did not oppose his election, as Joseph Mead and others did: but he now felt his position in the university insecure, looked to Lincoln's Inn as a refuge in case he were ousted from Cambridge, and as a last resort contemplated a migration to Basle.
Seeing that Preston's influence at court was waning, the fellows of Emmanuel petitioned the king to annul the statute limiting the tenure of their fellowships.
His will provided for his mother and brothers, founded exhibitions at Emmanuel College, and left his books and furniture to Thomas Ball, his favourite pupil and his minute biographer.
[1] Preston's early inclination for diplomacy was symptomatic of his character, which Fuller has summed as that of 'a perfect politician' apt 'to flutter most on that place which was furthest from his eggs'.