The Age of Faith is the name given to the period in history when religious belief was the dominant force in intellectual and cultural life. It is sometimes used as an alternative name for the Middle Ages (5th to 15th Century).
The Age of Reason, which succeeded the Age of Faith, is often known asThe Age of Enlightenment' or sometimes The Enlightenment. It is the period in intellectual history during which reason and intellect (as opposed to religious faith) were seen as the mainsprings of cultural and intellectual life. There is some debate about when The Enlightenment began, but the date is usually set somewhere between the middle of the 17th century and the beginning of the 18th century.