759. Similarly, although the Church offers for human faith alone certain particular facts of history, one who rejects them may easily be guilty of contempt or temerity. Such particular facts are: (a) apparitions of heavenly beings in post-Biblical times, such as the appearance of the Archangel Michael in Monte Gargano about 525 and the appearance of the Blessed Virgin at Lourdes in 1858, for which the Church has instituted feasts; (b) deeds related in the legends of the Saints, such as the victory of St. Catherine of Alexandria over the pagan philosophers and the carrying of her body to Mt. Sinai by Angels, which the Church inserts in the Breviary lessons; (c) the authenticity of relics. In granting certificates of genuineness, the Church guarantees only that there is sufficient historical evidence or probability for the belief that particular bones or other objects belonged to a particular Saint. 760. Many tenets of the Church, indeed, have not the prerogative of infallibility--for example, decrees of the Popes not given _ex cathedra_, decisions of Congregations made with Papal approval, teachings of Bishops to particular members of the Church, doctrines commonly held by Catholics as theological truths or certain conclusions. These decrees, decisions, etc., receive not the assent of Catholic faith, but what is called religious assent, which includes two things, viz., external and internal assent. (a) External assent should be given such teachings--that is, the homage of respectful silence due to public authority. This does not forbid the submission of difficulties to the teaching authority, or the scientific examination of objections that seem very strong.