I acknowledge that, according to their system, the affair of apparitions could be more easily explained; it is easier to conceive that a corporeal substance should appear, and render itself visible to our eyes, than a substance purely spiritual; but this is not the place to reason on a philosophical question, on which different hypotheses could be freely grounded, and to choose that which should explain these appearances in the most plausible manner, even though it answer in the most satisfactory manner the question asked, and the objections formed against the facts, and against the proposed manner of stating them. The question is resolved, and the matter decided. The church and the Catholic schools hold that angels, demons, and reasonable souls, are disengaged from all matter; the same church and the same school hold it as certain that good and bad angels, and souls separated from the body, sometimes appear by the will and with the permission of God: there we must stop; as to the manner of explaining these apparitions, we must, without losing sight of the certain principle of the immateriality of these substances, explain them according to the analogy of the Christian and Catholic faith, acknowledged sincerely that in this matter there are certain depths which we cannot sound, and confine our mind and information within the limits of that obedience which we owe to the authority of the church, that can neither err nor deceive us. The apparitions of good angels and of guardian angels are frequently mentioned in the Old as in the New Testament. When the Apostle St. Peter had left the prison by the assistance of an angel, and went and knocked at the door where the brethren were, they believed that it was his angel and not himself who knocked.[62] And when Cornelius the Centurion prayed to God in his own house, an angel (apparently his good angel) appeared to him, and told him to send and fetch Peter, who was then at Joppa.[63] St. Paul desires that at church no woman should appear among them without her face being veiled, because of the angels;[64] doubtless from respect to the good angels who presided in these assemblies. The same St. Paul reassures those who were with him in danger of almost inevitable shipwreck, by telling them that his angel had appeared to him[65] and assured him that they should arrive safe at the end of their voyage.