In 1682 he went to London, where he remained for six months, preaching on alternate Sundays in the Walloon church and in the Savoy Chapel. Due to political instability, he moved to Amsterdam, where he was introduced to John Locke and to Philipp van Limborch, professor at the Remonstrant college. He later included Locke in the journals he edited; and the acquaintance with Limborch soon ripened into a close friendship, which strengthened his preference for the Remonstrant theology, already favorably known to him by the writings of his grand-uncle, Stephan Curcellaeus (d. 1645) and by those of Simon Episcopius.