Islamic epistemology is similar to Western epistemology in terms of the problems it investigates. However, Islam recognizes that truth can be determined through a combination of methods including the empirical and the rational methods (Mumtaz Ali, 2009). In addition to these, Islam considers true reports by authentic authorities as truth as well. True reports include The Revelation which is the Qur’an, the authentic Hadith, and scientific reports of the authentic authorities. Reports by authentic authorities have to be subjected to internal and external criticism and have to meet with the criteria of true report (al-Attas, 1996). Hence, Islam establishes that knowledge of the nature of realities, the physical and the metaphysical, is possible and can be known with certainty. The source of all knowledge is God and it is the obligation of man to discover knowledge so that he can fulfill his purpose as servant and vicegerent of God on earth.
In the eighth century C.E., debates in Islamic epistemology were centered, among others, on reason and Revelation. The conservatives and the Ash’arites believed that Revelation was superior to reason which was in opposition to the Mu’tazilites’ view (Qadir, 1991). Qadir reports that the Mu’tazilites did not reject Revelation but believed that Revelation must be verified through reason. Qur’anic verses and hadith which were against the dictate of reason must be interpreted allegorically to discover their true meanings. In contrast to the above two views, several scholars such as al-Isfahani and al-Ghazali maintain that reason and Revelation are interdependent. Al-Isfahani argues that without reason, Revelation cannot be understood and without Revelation, “reason will not be rightly guided” (Mohamed, 2006: 148). Al-Ghazali describes the relationship between reason and Revelation is like the physical sight and the light ray (2007a). The physical sight cannot see without the light ray and the light ray is useless if the physical sight does not function.
In addition to arguments on reason and Revelation, Muslim philosophers (for example al-Kindi, 1974; Ibnu Sina, 1952; Miskawayh, 1963; al-Isfahani, 1987; al-Ghazali, 2007a, 2007b; Ibnu Rushd, 1976; Ibnu Qayyim, 2006) dealt extensively on the questions of the intellect, its meaning and its functions in relation to knowledge. The early Muslim philosophers also offered classifications of knowledge. For example, Ibn Sina presented a classification which he called a ‘Classification of the Intellectual Sciences’ in The Book of Healing and Treaties; al-Farabi in Ihsa al-‘Ulum; Ikhwan as-Safa’ in their Epistles; al-Ghazali in Ihya ‘Ulum al-Din; Fakhr al-Din al-Razi in The Book of Sixty Sciences; and Ibnu Khaldun in his Muqaddimah (Qadir, 1991).
Contemporary discourse in Islamic epistemology is on Islamicization of knowledge which prompted many intellectuals to study the Qur’an in order to establish theory and method of knowledge from the Islamic perspective (such as Wan Mohd Nor, 1989; al-Edrus, 1992; Mumtaz Ali, 2008). Al-Edrus (1992) investigated the Qur’anic concepts pertaining to knowledge and produced an introduction to the theory of knowledge in the Qur’an. He classified the Qur’anic concepts into six divisions which he further divided into two systems. One is system of general epistemology and another is system of Qur’anic epistemology. System of general epistemology consists of principle of normal stages of thought which begin with subhah (ambiguity), shakk (doubt), raib (fantasy), zann (conjecture), ‘ilm (knowledge) and end with yaqin (certainty).
There are three degrees of certainty in knowledge (Sharif, 1963; al-Edrus, 1992). The first and the lowest degree of certainty is ‘ilm al yaqin; the second is ‘ain al yaqin; and the third and highest degree of certainty is haqq al yaqin. ‘Ilm al yaqin is certainty arises from sound reasoning and judgment which is the result of man’s application of his intellect. The second degree of certainty, ‘ain al yaqin, is the certainty which is achieved from personal observation and investigation. The highest degree of certainty, haqq al yaqin, is the absolute truth with no possibility of error (al-Edrus, 1992). Haqq al yaqin is achieved from inner or personal experience. Inner experience is direct knowledge given by God through revelation, intuition and inspiration (Sharif, 1963).
To better understand the degrees of certainty, consider the following illustration. From a synthesis of data and information, a person makes a sound conclusion that philosophy really can enhance good thinking. At this point, that person achieved ‘ilm al yaqin for the certainty is gained from using his thinking abilities to make judgment on the available data and information about doing philosophy. To be more certain of his conclusion, he made an investigation to measure the effects of doing philosophy in promoting good thinking. He now has the evidence from his own personal observation and investigation that philosophy do enhance good thinking. At this juncture, he has achieved ‘ain al yaqin. ‘Ain al yaqin is not certainty from seeing for vision is unreliable but certainty from having proven the truth through investigation. Convinced on the result of doing philosophy to enhance good thinking, that person studies and applies philosophy. He has personally experienced how doing philosophy has improved his thinking ability. He is now totally convinced that philosophy could enhance good thinking, thus he has achieved haqq al yaqin. Knowledge of a Muslim should progress from ‘ilm al yaqin to ‘ain al yaqin to haqq al yaqin. It is not enough to know for certain but to confirm it by proving and applying it.
Other principles of system of general epistemology are the principle of intellect as the tool of knowledge and the principle of truth as the goal of the intellect (al-Edrus, 1992). Al-Edrus further explains that the system of Qur’anic epistemology comprises principles of The Revelation as the means of knowledge, conceptual framework of The Revelation [ayat (signs), amthal (examples), and asma’(names)], and the principle of the division of ayat into muhkamat (categorical) and mutashabihat (allegorical). The relationship between the general and the Qur’anic epistemology is grounded on the relationship between the intellect and The Revelation. Al-Edrus concludes that the Qur’an purifies the intellect from hawa (desires) and ghafala (unconsciousness) hence becomes a reliable source of knowledge through zikr (contemplation) and huda (guidance). However, the intellect in its purified state is limited to know metaphysical truths thus The Revelation becomes the source of knowledge of metaphysics.
The current movement in Islamic epistemology includes critical analysis and evaluation of the foundation and method of Western knowledge based on the criteria of knowledge from the Islamic perspective (such as al-Attas, 1993; Safi, 1996; Mumtaz Ali, 2008, 2009; Akdogan, 2008). Mumtaz Ali (2008) argues that in order to produce knowledge from the Islamic perspective, the method used in producing knowledge should also come out of the Islamic worldview. He examines the Qur’anic verses on the significance of using the faculty of the senses and observation. He, therefore, produces method of knowledge which is based on the Qur’anic guidance. Knowledge is produced through the method of observation by sense perception which is confirmed through experimentation and reflection. This process is conducted under the guidance of the Revelation. Further, contemporary Islamic epistemology also involves critical analysis and evaluation of Islamic turath to make judgment on its usefulness and relevancy for the present time (such as initiative by the International Institute of Islamic Thought).