The basic meaning of Ishraq (Illumination) is "rising," more precisely "rising of the sun." The term is used extensively in Arabic and Persian philosophical texts, signifying a special intuitive mode of cognition with no temporal extension, spatially coordinated "in" the knowing, self-conscious subject. In other words, it applies to the relation between the known and the knower. The term Ishraq in its general, non-technical usage in ordinary language, signifies the "mystical" as well as the range of extraordinary types of knowledge, including personal inspiration arriving spontaneously from the unknown (elhām).
The word Ishraq also means "facing towards east," and Ishraqiyun, the followers of the Ishraqi path were the people who did not loose sight of the inner east, the direction where divine light and the light of self-consciousness rises.
The crucial notion for Ishraq philosophy is knowledge-by-presence (ilm al-huduri). This has often been related to intuitive knowledge, and results in attempts to unravel the mysteries of nature not through the principles of physics but through the metaphysical world and the realm of myths, dreams, fantasy and truths known through inspiration. The distinction between scientific knowledge and knowledge-by-presence is crucial for Suhrawardi, who claims that the essence of human beings lies in their self-awareness, through the luminosity of their own inner existence.
Ishraq uses a language of light to describe the whole continuum of reality, which consists of four levels: intellect, soul, matter and the imaginal realm. This fourth realm is describable as of possibilities prior to taking on shape, that is, before they receive luminosity from the One Source, the Light of Lights. The light received is essentially the same, and the luminous thing differs from other light entities only in respect of degrees of intensity. Luminosity flows eternally, and gives shape to the forms, thus making the entity visible and known. The difference between things, then, lies not in their essences but in the degrees of intensity of the shared essences. All luminous things constitute an aggregate whole and are co-eternal with the Light of Lights. The Light of Lights is one, but is neither beyond being nor nonbeing, nor does it have a will. Everything in the continuum is generated from the Light of Lights and shares a degree of light similarity.