Ibn Sina considered the way of viewing non-material (rational) beings to have a reverse process of viewing material beings. After him, Sheikh Eshraq (Suhrawardi) also explained how to observe the creatures of the imaginal world with the help of this process. Instead of the five external senses that send information to common sense, this information is transferred from the soul or the imagination in the opposite direction to common sense. The necessary condition for this is that the external and internal powers are not busy, and there is an opportunity for sensual perception to affect the brain and common sense. In this way, an unseen being is represented by the person. This process happens in two states: sleep and wakefulness. Those whose souls are strong or whose bodies are weak succeed in such an observation. Since sensual perception reaches a common sense through inner powers and imagination, sometimes imagination interferes, takes possession of it, and turns what the soul has observed into its likeness or opposite. In this case, we need an interpretation of the conditions and methods examined in this article. However, in some cases, what has been observed reaches the common sense without interference, and the person observes them. The criterion for such an observation is that closing the eyes does not prevent it from being seen. In some cases, this process requires an interpretation, and this article examines the conditions. Also, this process has various applications in Islamic philosophy. With its help, the method of observing and representing angels, jinn, and demons, as well as the method of inspiration and seeing a veridical dream, and some types of magic and knowledge of the occult have been explained. In this way, it is also possible to explain the observations and sensory perceptions and hear the sounds described by Sheikh Eshraq in the stages of treading a path of mystical conduct. The types of revelation that happen through seeing the angel of revelation and hearing his voice can also be explained in this way. In some patients, the origin of these observations is purely imaginary, and the person suffers from hallucinations and observes things that have no origin other than his brain. In this way, the delusions of some patients can also be explained. This article describes and criticizes the reverse process and its applications. It has been shown that Avicenna influences Suhrawardi in this discussion, and both philosophers have proposed similar applications for this theory, with the difference that Suhrawardi extended Avicenna's thesis, which was about rational beings, to the imaginal world.