When there were contending religions, each side would apply skepticism to the knowledge claims of the other. The Catholics used skepticism to disprove the claims about knowledge of God made by the Protestants, and the Protestants did the same thing to the Catholics. The result was that each side ended up extolling its own type of faith, rather than the knowledge claimed by the other side. (This use of skepticism to elevate faith and mysticism had its roots in Islamic philosophy, specifically in the writings of Abu Hamid al-Gazali [1058–1111]). As the two-sided religious skeptical debates wore down, the modern form of skepticism, which supports observation and the scientific method, came into wide use.