Abstract

The Qur'an is one of the fundamental origins of the hypothetical and categorical reasoning in the Shari’a and experimental sciences in the Muslim world: the concept of certainty in the Qur'an signifies decisiveness and its antonym is presumption. In the fundamentals of the Islamic jurisprudence, Al-Shatiby listed the descriptions of peremptory science in three characteristics: to be general and unchanging (free from extremes) ,constant and dominant (governorship). He considered the shari’a evidences to be suspicious and will never be decisive unless they are all englobed in one meaning; this is known as the method of induction. In the empirical sciences, Muslims distinguished between skepticism and decisiveness: Jaber bin Hayyan refuted the certain knowledge which is derived from the usual practices and considered the inference by syllogism to be doubtful. In Avicenna's view, single fundamentals of deduction are not useful to get certainty, just like an experiment alone, because it needs to be viewed and measured, and he confirmed that certainty is reached through evidence and sensory induction. Ibn al-Haytham pointed out that syllogism has traits of presumption and probability, and that doubt is not a way to reach proof, whereas full induction is regarded as a path to certainty. As far as Al-Biruni is concerned, the predominant assumption is an acceptable proof for reasoning in historical studies and is not acceptable in experimental studies.