The First Vatican Council

The same holy Mother Church holds and teaches that God, the beginning and end of all things, may be certainly known by the natural light of human reason, by means of created things; 'for the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made,' but that it pleased his wisdom and bounty to reveal himself, and the eternal decrees of his will, to mankind by another and a supernatural way : as the Apostle says, ' God, having spoken on divers occasions, and many ways, in times past, to the Fathers by the Prophets; last of all, in these days, hath spoken to us by his Son.' It is to be ascribed to this divine revelation, that such truths among things divine as of themselves are not beyond human reason, can, even in the present condition of mankind, be known by every one with facility, with firm assurance, and with no admixture of error.