Sohrevardi, as an illuminationist, had very significant innovations in philosophy, mysticism and spiritual thought. The essence, reality and the quality of achieving spiritual experiences, which have received special attention by different people in different cultures and schools of thought, are among the innovative domains of Sohrevardi’s system of thought. There are two major views on the essence of these experiences: first, essentialism which emphasizes their coherence and commonality among different people and schools of thought, and second, constructivism in which mystical intuition plays an important role in the creation of numinous experience. These different views indicate the differences which different schools of thought haveabout the quality of these experiences. From Sohrevardi’s perspective, the unity with the Light makes mystical illumination and numinous experiences possible. Accordingly, the individual’s special view on soul and his/her psychology are involved in the fulfillment of these experiences which are accompanied with illumination, observation, unity and extinction in unity. Therefore, Sohrevardi’s views on the features of numinous experience represent a kind of essentialism in these illuminations. This does not mean that the unity of these personal experiences consistent with the individual’s thought makes them different from each other. They rather have similar and common characteristics. The present study, as a library research, adopting a descriptive analytical method provides evidence which shows Sohrevardi’s viewpoints on the principles of essentialism in mystical illumination. It also provides answers to a number of relevant questions in this area of inquiry.