 The effect of the Salters' Hall conference (1719), called for by the views of James Peirce (1673–1726) of Exeter, was to leave dissenting congregations to determine their own orthodoxy; the General Baptists had already (1700) condoned defections from the common doctrine.Leaders in the advocacy of a purely humanitarian christology came largely from the Independents, such as Nathaniel Lardner (1684–1768), Caleb Fleming (1698–1779), Joseph Priestley (1733–1804) and Thomas Belsham (1750–1829).Isaac Newton was an anti-Trinitarian, and possibly a Unitarian (though he may have been Sabellian).