The Enlightenment in England was both 'conservative' and 'liberal' in character. This helps to explain John Wesley's attitude towards it. He accepted, with reservations, Locke's theory of knowledge, Newtonian natural philosophy and Hartley's psychology, partly because they seemed to support, or at least be congruent with, traditional Christian doctrines. He welcomed the practical application of the new science, e.g. in the medical use of electricity. Certain idea which he had inherited, such as the 'reasonableness' of Christianity (however that concept is interpreted) fitted the newer ways of thinking.
Wesley did not sympathize with calls for change in the established political order, although he criticized specific policies and abuses. He believed that Great Britain and her colonies enjoyed as much civil and religious liberty as they could legitimately desire. 'Civil liberty' refers particularly to the rule of law; 'religious liberty' to freedom of worship. He opposed American independence and rejected Price's political theory. Perhaps inconsistently, he condemned the institution of slavery. Wesley vigorously criticized representative figures of the French and Scottish Enlightenments, including Voltaire, Montesquieu, Raynal and (especially) Rousseau on the one hand, and Hume, Lord Kames and Robertson on the other.