Fides et Ratio (Latin: faith and reason) is an encyclical promulgated by Pope John Paul II on 14 September 1998. It deals primarily with the relationship between faith and reason. The Pope posits that faith and reason are not only compatible, but essential together. Faith without reason, he argues, leads to superstition. Reason without faith, he argues, leads to nihilism and relativism. He writes: Although reason creates a "systemic body of knowledge," the Pope avers, its completeness is illusory: Without a grounding in spiritual truth, he continues, reason has: