There are two kinds of revelations: (1) universal revelations, which are contained in the Bible or in the depositum of Apostolic tradition transmitted by the Church. These ended with the preaching of the Apostles and must be believed by all; (2) particular or private revelations which are constantly occurring among Christians (see CONTEMPLATION). When the Church approves private revelations, she declares only that there is nothing in them contrary faith or good morals, and that they may be read without danger or even with profit; no obligation is thereby imposed on the faithful to believe them. Speaking of such revelations as (e.g.) those of St. Hildegard (approved in part by Eugenius III), St. Bridget (by Boniface IX), and St. Catherine of Siena (by Gregory XI) Benedict XIV says: "It is not obligatory nor even possible to give them the assent of Catholic faith, but only of human faith, in conformity with the dictates of prudence, which presents them to us as probable and worthy of pius belief)" (De canon., III, liii, xxii, II). Illusions connected with private revelations have been explained in the article CONTEMPLATION. Some of them are at first thought surprising. Thus a vision of an historical scene (e.g., of the life or death of Christ) is often only approximately accurate, although the visionary may be unaware of this fact, and he may be misled, if he believes in its absolute historical fidelity. This error is quite natural, being based on the assumption that, if the vision comes from God, all its details (the landscape, dress, words, actions, etc.) should be a faithful reproduction of the historical past. This assumption is not justified, for accuracy in secondary details is not necessary; the main point is that the fact, event, or communication revealed be strictly true. It may be objected that the Bible contains historical books, and that thus God may sometimes wish to reveal certain facts in religious history to us exactly. ...