Calvinists have taught that a gradual process of corruption was predicted in the New Testament, that this process began within the New Testament era itself, and culminated in a self-proclaimed corrective brought about by the Protestant Reformation. The Roman Catholic and Eastern Orthodox Churches had developed from early on the idea of infallibility of the Church – that the Church may speak entirely without error in particular councils or edicts; or that, in a less definable way, the Church is infallibly directed so that it always stands in the truth and indeed that the Church has the promise of Jesus that it shall do so. The Roman Catholic Church also developed on the parallel and complementary idea of papal infallibility – that the pope may speak in the same capacity; this idea was finally defined dogmatically at the First Vatican Council of 1870 and incorporated into doctrine.