Exploration and Assessment of the Standard for Correspondence between Subject and Object according to Muslim Philosophers

For man's access to knowledge of the external world, there should be, firstly, forms of things in the mind; secondly, such mental forms should represent the external things; thirdly, these representations should correspond to the things existing in the external world. Representation of the external world by mental forms, or in other words, existence of some sort of relation between the subject and object seems to be evident. But explanation of the way that these forms represent the external world and relate to the objective things has caused many debates among Muslim philosophers some part of which has been introduced under "mental existence". Presumption of discussions about mental existence is that there is some sort of relation between mental existence and the external world. The focus of discussions about mental existence is explanation of the nature of this relation and clarification of the point that what in man's mind is which is taken as a standard for knowledge and links our impressions to the external things. In the Islamic philosophy, concerning mental existence and the way that mental existence relates to the external world, totally four theories have been introduced. According to the Muslim philosophers, mental existence and external thing are united in quiddity, and what that comes into existence in the mind is the same as their quiddity. Some Muslim theologians have rejected the [notion of] mental existence, and think that knowledge and mental forms are of the kind of relation. Some other Muslim philosophers and theologians, though they have accepted mental existence, think that mental forms are images of the external thing and not the same as its quiddity. Criticism and assessment of these theories is the subject matter of this article.