. . . the son of a citizen of Oxford, was born in 1602; Laud, then a Fellow of St. John’s, was his godfather. Entered at Trinity College in 1618, he graduated two years later, and, in 1628, he was elected a Fellow of his College. He took from the first an active part in the “Romish” controversy, which then agitated the University, frequently meeting in debate one John Fisher, a Jesuit, who ultimately convinced him that the only refuge from distracting religious conflict was in the bosom of the infallible Roman Catholic Church. Chillingworth went to Douay in 1630, but returned to Oxford in the following year, and, three years later, declared himself to be again a Protestant, though not yet an Anglican. It was not till after the publication of his great work, The Religion of Protestants a safe way to Salvation, that he consented to subscribe the Articles, and accept the Chancellorship of Salisbury. Chillingworth was a close friend of Lord Falkland, and with him took the side of Charles the First against the Parliament. He was taken prisoner on the fall of Arundel Castle, where he had lain ill during the siege, and was almost literally talked to death in January 1644 by Francis Cheynell, a Puritan minister, who attended his funeral, and buried his “corrupt rotten book” with him.
"John Fisher" was the alias of Father John Percy, SJ--and choosing the name of the great Bishop of Rochester and martyr, John Fisher, was a great gesture of honor and admiration for a Catholic hero--and Father Percy/Fisher was much involved in the Jesuit mission to England:
Born at Holmeside, Durham, 27 Sep., 1569; died at London, 3 Dec., 1641. Converted when only fourteen years, he went first to Reims, in 1586, then to the English College, Rome, 1589-94. Returning to Belgium, he entered the Jesuit novitiate, 2 May, 1594, and then set out for England in 1596. He was, however, arrested by the Dutch, tortured, and sent prisoner to London. He managed to escape, and became the companion of Father Gerard in several adventures. He was seized at Harrowden (November, 1605) at the time of the Gunpowder Plot, but was eventually banished at the request of the Spanish ambassador (1606). Retiring to Belgium he was for a time head of the English Jesuits, then professor of Scripture at Louvain, after which he returned again to England, and was again imprisoned and condemned to death (1610): He had already begun to write on current controversies, and when James I desired a series of disputations in 1622, Percy, who was then in a prison in London, was required to defend the Catholic side. In these disputations King James himself and Laud took a leading part. As a result of these disputations, Mary Countess of Buckingham, and Chillingworth became converts to the Church. These controversies were afterwards printed and discussed by Percy and Floyd on the Catholic side, and by Laud, Francis White, John White, Featley, and Wotton on the Protestant. Percy was eventually released in 1625 and ordered to banishment in 1635, but he was suffered to remain in London till his death.
For more information about Father John Floyd, SJ, with whom Father Fisher worked, see the Catholic Encyclopedia entry. That Chillingworth was not prosecuted for his conversion, and that Father Fisher was never executed, but in fact asked/commanded to engage in theological disputation, exiled twice, and shown mercy, demonstrates at least some of the leniency toward Catholics that we find in James I's reign.