Numen (Noumenon) or Ding an sich, "what is in itself" means, in Kant's philosophy, the "reality", which is unknowable and unidentifiable beyond phenomena, "true knowledge". Numen, which is an effort to define the real essence behind the image of the object with which the subject relates, within the framework of thoughts about the possibility or impossibility of knowledge, is the opposite of the "phenomenon" in which the concrete finds expression and expresses the existential essence. It occurs within any entity, independent of our perception.