Together with John Keble and Edward Pusey, Newman was one of the founders of the Oxford movement or Tractarian movement within the Church of England in 1833. This high-church movement foundered with Newman’s own conversion to Roman Catholicism in 1845. Philosophically Newman is remembered for his idea of conviction arrived at rationally, but in an informal way, conditional upon pre-existent immersion in a subject matter and its associated practices. The idea is elaborated in terms of an ‘illative sense’ or internal subjective authority that leads to our sense of the truth of propositions in all ‘concrete reasonings’ including science, history, and theology. This idea can be seen as anticipating much in later twentieth-century epistemology, especially that of Wittgenstein. The principal work is Essay in Aid of a Grammar of Assent (1870).