To the Sufis, light also represents what we know about our inner self, and darkness what we do not know.[20] Ibn Arabi distinguished three types of light: Nûr al-anwâr (The Light of lights), which reveals the absolute reality in its most transcendent aspect, anwâr al-ma'âni (The Light of the intellect) and anwâr al-tabi'â (The Light of nature).[21] The Kurdish philosopher Shahab al-Din Suhrawardi (1155–91) wrote, "Allah's essence is the original creative Light, always illuminating existence.