[Milesian]

To bring contempt and odium on the mystic Spouse of Christ, who is the true light, the children of darkness have been wont to cast in her face before the world a stupid calumny, and perverting the meaning and force of things and words, to depict her as the friend of darkness and ignorance, and the enemy of light, science, and progress
(Motu-proprio, Ut mysticum, 14 March, 1891).


Apply yourselves energetically to the study of natural sciences: the brilliant discoveries and the bold and useful applications of them made in our times which have won such applause by our contemporaries will be an object of perpetual praise for those that come after us
(Leo XIII. Alloc., March 7, 1880).