Richard Baxter (1615–91) was possessed of that all-embracing curiosity, indefatigable energy and tenacious idealism which, as Reformation and Renaissance passed into the sober Augustan certainties of the Enlightenment, became ever rarer among Englishmen. His many-sidedness is reflected in the very different kinds of interest his career attracts. The ecclesiastical historian meets in Baxter both puritanism's most committed apologist and its most idiosyncratic representative, a man who, involved in every doctrinal controversy and every negotiation or conference convened to discuss a national church settlement, was to have a lasting influence on English Dissent. His participation in these debates is, however, more than a chapter in the history of later puritanism: it contributed to the development of seventeenth-century rationalism and liberalism and shows suggestive affinities with the thought of the Cambridge Platonists. There is, furthermore, contemporary relevance in Baxter's conception of ‘mere Christianity’: ‘the first exponent of Ecumenism in England’, he promoted ecclesiastical reconciliation, both practically, in the Worcestershire Association, and theologically, in the attempt of such treatises as Richard Baxter's Catholick Theologie (1675) to harmonise Calvinism and Arminianism.