Al-Farabi, al-Ghazali, and Nasir al-Din al-Tusi: Classification of the Sciences and the Place of Religious Sciences

Classification of the Sciences has always been an essential part of the Islamic scientific thought. This was due to the significant role of science in the Islamic culture and as well as the development of various scientific traditions in this civilization.
Philosophy of science, today, discusses the classification of sciences in which methods, subject matters, and goals of the science are studied. In addition, the discipline takes into consideration the scientific principles and foundations involved.
In order to study this issue from the epistemological viewpoint it is necessary to pay attention to two problems: first are the intellectual foundations of its classifier and second is the relative realization of this classification in the scholarly milieu. This was achieved in regards to the religious sciences and their co-existence with secular sciences since a long time ago, but this was questioned in recent centuries after the introduction of modern epistemology.
This paper examines three types of the important classifications in Islamic civilization proposed by Farabi, Ghazzali and Nasir Al-din Tusi and studies the formation of this historical experience, which is a religious understanding of all sciences and epistemological compatibility between religious and secular sciences.