Islam has experienced the era of rational thinking. There have been dissenters to the literalist Islamic worldview. Their message was that the primary and secondary sources of Islam must not be taken literally, but conceptually.

At stake is the fundamental principle of the 'Word of God' in the Quran, which traditionalists (those protecting the sanctity of the orthodox beliefs) claimed to be literal, final and unchangeable. To them, revelation always ruled over reason.

From our modern perspective, also at stake is the contention that the literalist Muslim 'thinking norm' does not have any avenue for realising its own mistakes.

A single example would hope to portray the point. Surah 55.5 of the Quran states that herbs and trees bow down to God. Orthodox Muslims believe that the word of God is not to be changed, so they contend that herbs and trees do indeed bow down to God in a manner that humans would perceive and perform this, by lowering their heads.

Al-Kindi (d. 803), an eminent Islamic scholar, pointed out that the word 'bow' in this context should not be taken literally, for herbs and trees do not have the head, nor the bones and muscles for this very human action.

He said that, in this context, the world 'bow' should be conceptualised - to make obeisance seems most apt in this instance. The point he was making was that God's words must be taken not literally, but conceptually. In other words, reason should prevail over revelation.

Reformist or radical early Muslim thinkers, known as the Mu'tazilites, would initiate a new body of Islamic wisdom based on reason or on conceptualisation, known as ijtihad (independent reasoning).