1584-1666 1596-1650 17thcentury 1823-1892 1882-1973 1884-1978 1905-1980 19thcentury 921descartes authors biography christianity correspondence correspondencegilson correspondencemaritain descartes ernest etienne existentialism france frans french general gilson hals history intellectuallife jacques jean-paul maritain modern phi009000 philosophers philosophy renan rené sartre science surveys