Within theological circles in our times there can scarcely be a proposition less likely to meet with approval than that which, on 24 April 1870, the first Vatican Council decreed to be a matter of faith, to be upheld by all Christians, namely: that God, the source and end of all things, can be known with certainty from the consideration of created things, by the natural power of human reason: ever since the creation of the world, his invisible nature has been clearly perceived in the things which have been made [Rm 1, 20].