Alphonse-Joseph-Auguste Gratry (1805-1872) was born in Lille, northern France, of irreligious parents and lived during a time of endless revolution. As a young man, he underwent a powerful conversion in which he experienced a mystical vision of a world based on truth and justice. This determined the course of his future life. A classically educated scholar, he studied engineering at the outstanding ?cole Polytechnique, completed a doctorate on the...