In European tradition, aside from the decree of religious toleration by Constantine I at Milan in 313, the philosophers Themistius, Michel de Montaigne, Baruch Spinoza, John Locke, Voltaire, Alexandre Vinet, and John Stuart Mill and the theologians Roger Williams and Samuel Rutherford have been considered major proponents of the idea of Freedom of Conscience (or 'soul liberty' in the words of Roger Williams).