Islam affords the faculty of human reason with a lofty status. It is what allows us to think, contemplate, and draw conclusions. It is what gives us the ability to develop the Earth on which we live. The Quran highlights this point from many different angles:
1. Allah singles out the people who possess reason and proper knowledge as being those who carry out the objectives of worship. He discusses the rulings of how to perform the pilgrimage and then concludes by saying: “And fear me, O people of understanding.” [ Surah al-Baqarah : 197]
2. Allah declares that the ability to receive benefit from remembering Him and from hearing exhortations to truth and righteousness is the exclusive quality of those possessing reason. He says: “In their stories is a lesson for those possessing reason.” [ Surah Yûsuf : 111]
He also says: “And We have certainly left of it a sign as clear evidence for a people who use reason.” [ Surah al-`Ankabût : 35]
3. Allah honors the faculty of reason and makes it the crux of our legal accountability. The Prophet of Allah (peace be upon him) said: “The pen is lifted from three people: the sleeper until he awakens, the child until he reaches the age of discernment, and the insane until he is able to reason.” [ Sunan al-Tirmidhî (1423) and Sunan Ibn Mâjah (2042)]
4. Allah reprimands those who unthinkingly follow in the footsteps of their forefathers who in doing so shun the dictates of reason. He says: “And when it is said to them to follow what Allah has revealed, they say: ‘Nay, we follow what we found our fathers upon.' Even though their fathers could discern nothing of reason and were not rightly guided.” [ Surah al-Baqarah : 170]
5. Islam has made it unlawful to compromise the faculty of reason in any way. It forbids intoxicants and narcotics. Allah says: “O you who believe! Intoxicants, games of chance, sacrificing on stone alters, and divining arrows are the filth of Satan's handiwork, so keep away from it that perchance you might be successful.” [ Surah al-Mâ'idah : 90]
Umm Salamah relates to us that the Prophet (peace be upon him) forbade every intoxicating and narcotic substance. [ Sunan Abî Dâwûd (3686) and Musnad Ahmad (26634)]
6. Islam strictly prohibits every practice that offends reason or runs contrary to it, like seeing evil omens, resorting to soothsayers and fortunetellers, divination with sand or seashells, and all other deviant and superstitious practices.
In Islam, there are two sources of knowledge:
This is the truth that is conveyed to us from Allah by way of His Prophets (peace be upon them).
This is the truth that is achieved through the combined efforts of our sensory observations and our faculty of reason.
From this, we can appreciate Islam's balanced approach to the relationship between reason and revelation. Ibn Taymiyah writes:
Reason is a precondition for knowledge and for the proper performance of our actions. By it, knowledge and action are perfected. However, it does not stand independently in this capacity. It is but an innate ability like the eyesight of our eyes. If the light of faith and of the Qur'ân reaches it, it is the same as when the light of the sun or of a flame reaches our eyes. If it is kept isolated, it cannot perceive the matters that it is unequipped to perceive on its own. If it is taken away completely, words and deeds become nothing more than animal behaviors, experiencing likes, emotions, and tastes in the same way that cattle might experience them. Therefore, deeds carried out in the absence of reason are deficient and words spoken contrary to reason are false. [ Majmû` al-Fatâwâ (3/338)]
Reason does not play the same role in all fields of knowledge. In this respect, knowledge can be broken down into three categories:
This is knowledge of that which cannot be doubted by any rational person. Every reasoning soul must possess this knowledge. This includes a person's knowledge of his own existence, that two is greater than one, or that the sky is above us and the ground below us.
This is knowledge that is acquired through and gleaned from evidence. Such thinking must draw from essential knowledge in order for its correctness to be discerned. Many disciplines fall into this category, like the natural sciences, medicine, and various manufacturing arts. It is in these fields where reason plays its greatest, most critical, and most constructive role.
Knowledge of the Unseen:
These are matters that reason alone cannot arrive at. For a person to arrive at such knowledge, some other source of information is needed. This includes knowledge of what is to be found in some distant land or knowledge of the events of the Hereafter, like the resurrection and the judgment. Such knowledge is only ascertainable by way of a report. When the questions at hand are those of religious faith, especially with respect to the particulars, then the only source that can be relied upon is divine revelation.
This is the balanced approach to reason and revelation. It can be contrasted with the approaches of various deviant sects. Some of them, like the Peripatetic philosophers, relied exclusively upon reason and eschewed revelation in its entirety. Others, like the majority of the scholastic theologians, discounted the purport of revelation where they presumed it to contradict with the dictates of reason. Others, like some of the Sufi sects, took personal inspiration and spiritual experience as the basis of truth even when it contradicted with both reason and revelation.
In order to appreciate the proper role of reason and accurately define its limitations, we should consider the following. Each of our senses has its limits of strength and its particular domain. Any attempt to employ one of the senses beyond its scope is an exercise in futility that might also prove injurious to the one attempting to do so.
For example, the eye provides us with the ability to see objects. However, regardless of how healthy and acute a person's eyesight might be, it cannot be used unaided to see microbes, in spite of the fact that microbes most surely exist. Likewise it cannot hope to see the colors of the Infrared or Ultraviolet spectrums of light. If a person tries to force his eyes to view these things, he will never succeed in doing so, though he might succeed in damaging his vision.
Likewise, the intellect has its limits. It cannot ascertain on its own all truths and all forms of knowledge. People believe in and accept things that their senses cannot perceive and that their intellects cannot comprehend. For instance, our intellects accept the phenomenon of gravity though we are of yet unable to comprehend its true nature. We can explain electricity as electrons moving from a negative to a positive charge. However, the true nature of the subatomic world still eludes us.
Among what must remain beyond the scope of our reason are matters of the Unseen. We can say with confidence that whatever falls squarely into the domain of the Unseen falls outside the domain of our intellects. For example, we know that when the body of the deceased is placed in its grave, its soul is returned to it then two angels approach that soul to question it. This is established by authentic hadith. How is the soul returned? Why doesn't his body stir and cry out at this time? How is his grave made spacious for him to the extent of his vision if he is among the righteous? Questions like these cannot be answered by our intellects. Our rational faculties are limited in their scope and cannot investigate matters that pertain exclusively to the world of the Unseen.
Our intellects must accept such matters if we come to know of them by way of divine revelation from Allah to His Messengers (peace be upon them). We are limited in our knowledge of these matters to what the sacred texts inform us about them and we cannot delve into their true nature or speculate on them any further. If we attempt to do so with our intellects, we will not arrive at any results, though we might bring harm to our faculties of reason in the attempt. This has been the plight of the philosophers and others who have tried to use reason to acquire knowledge of things wholly outside the world of human experience.
It is in light of this understanding that Allah says: “And those of firm knowledge say: ‘We believe in it. All of it is from our Lord.' And none take heed except people of discernment.” [ Surah Âl `Imrân : 7]
This was the approach of the Salaf , our pious predecessors. They knew the limits of reason and stopped at those limits, never attempting to use their rational faculties to plumb the depths of the Unseen. They did not ponder on the true nature of Allah, His essence, and His attributes. They voiced their objections to this pursuit and forbid others from engaging in it. In this way, they safeguarded themselves from doubt and error and kept their hearts secure in the certainty of faith.
We can actually use reason to argue against those who advocate the application of reason to these questions. We can say to them: It is a fact that rational minds differ in their strengths and abilities. Whose mind, then, must we give preference to when it is at variance with the texts? Why should we submit to the intellect of any human being? Moreover, any given mind is prone to change its opinions as it acquires new knowledge or as it contemplates and reviews matters more thoroughly. This means that we will be obliged to adhere to one viewpoint today and possibly a wholly different one tomorrow. Because minds differ so much, we will be subjected to a whole range of conflicting and often irreconcilable opinions that will consign us to confusion and doubt. Experience has shown us that many of those who have subjected the sacred texts to the rule of reason had later abandoned that approach as being in error.
It is one of the blessings of Allah upon the Muslims that he has sufficed them regarding matters of the Unseen. He revealed to them the Qur'ân and took its preservation upon Himself and He sent them the Messenger (peace be upon him) and preserved for them the Sunnah of that Messenger. In this way, he sufficed them in their knowledge of the Unseen, so they would not have to squander their intellectual powers trying to investigate matters that their minds are unable to cope with. In this way, He freed their minds to pursue the problems of their worldly existence and derive benefit from the world in which they live.
Sayyid Qutub writes:
There is no other religion that so honors the human intellect, awakens it, sets it on the right course, and mobilizes it for constructive effort, liberating it from the shackles of fables and superstition, and the oppression of soothsayers and possessors of “forbidden knowledge”. At the same time, it safeguards the mind from straying outside of its proper domain and into an intellectual wasteland without a guide. There is no other faith that has done this quite as Islam has. [ Khasâ'is al-Tasawwur al-Islamî (49)]
He also observes:
The conceptual framework of Islam – in what is beyond the basis of this conceptual framework and its fundamentals – affords the human intellect and human knowledge a vast and total field of endeavor. It does not impede the mind or stand in its way of investigating the universe. Rather, it calls upon it to investigate and spurs it on. [ Khasâ'is al-Tasawwur al-Islamî (71)]
Among the gems of what al-Ghazâlî said in his later life is that Allah has sufficed the Muslims in the matters of their faith and commanded them to follow, while opening up to them the matters of the world and commanding them to be innovative. However, some Muslims instead opted to be innovative and inventive in matters of faith, while in the affairs of the world, they sufficed themselves with following the nations of the East and West without contributing any development or any new ideas.