Murtada Mutahhari describes Kalām as a discipline devoted to discuss "the fundamental Islamic beliefs and doctrines which are necessary for a Muslim to believe in. It explains them, argues about them, and defends them" (see also Five Pillars of Islam). There are many possible interpretations as to why this discipline was originally called so; one is that the widest controversy in this discipline has been about whether the "Word of God", as revealed in the Quran, can be considered part of God's essence and therefore not created, or whether it was made into words in the normal sense of speech, and is therefore created.