 During this period Collins also met Samuel Bold and John Toland. From 1703 until 1706, after his wife’s death, Collins spent the winters in London and the summers at his fine summer mansion in Buckinghamshire—where Queen Anne and her court visited him. In 1707 Collins began a pamphlet controversy with Samuel Clarke, a prominent British philosopher and member of Newton’s inner circle, over the question of whether matter can think. The controversy continued until 1708. In 1707 Collins also published anonymously the Essay Concerning the Use of Reason in Propositions, the evidence whereof depends on human testimony. During this period Collins frequented the London coffee shops where the deists and free-thinkers met. Berkeley apparently met him at such a gathering in 1713. In 1710 Collins made his first trip to the Continent, spending his time buying books in Holland and meeting John Churchill, first Duke of Marlborough, and Prince Eugene. Back in England, Collins met several times with Samuel Clarke and William Whiston at the house of Lady Calverly and Sir John Hubern for “frequent but friendly debates about the truth of the Bible and the Christian Religion” (Whiston, quoted in O’Higgins 1970: 77). In 1713 he published A Discourse Concerning Free-Thinking. The Discourse was his most controversial work. He made a second trip to the continent about the time that the Discourse was published. Again he went to Holland and France and planned to go on to Italy. The trip was cut short by the death of a close kinsman. In 1715 Collins, in effect, took root in Essex, moving into Mowdon Hall. Collins probably owned a good 2000 acres in Essex, much of it prime agricultural land. In 1717 he published A Philosophical Enquiry Concerning Human Liberty in which he argues for a compatibilist form of determinism and rejects freedom of the will. Samuel Clarke reviewed the book, continuing the argument that had begun during the Clarke Collins correspondence of 1707–08.