Noun
The of itself unknown and unknowable rational object, or thing in itself, which is distinguished from the phenomenon through which it is apprehended by the senses, and by which it is interpreted and understood; -- so used in the philosophy of Kant and his followers.
Source: Webster's dictionaryNOUMENON, n. That which exists, as distinguished from that which merely seems to exist, the latter being a phenomenon. The noumenon is a bit difficult to locate it can be apprehended only by a process of reasoning which is a phenomenon. Ambrose Bierce
Plotinus argues of the disconnect or great barrier that is created between the nous or mind's noumenon (see Heraclitus ) and the material world ( phenomenon ) by believing the material world is evil. Source: Internet
The noumenon was what Kant called the Ding an sich (the Thing in Itself), the reality that is the foundation of our sensory and mental representations of an external world. Source: Internet
The true reality in Huayan, the noumenon, or "Principle" is likened to a mirror, while phenomena are compared to reflections in the mirror. Source: Internet
It is for this reason that Schopenhauer identifies the noumenon with what we call our will. Source: Internet
Schopenhauer begins by arguing that Kant's demarcation between external objects, knowable only as phenomena, and the Thing in Itself of noumenon, contains a significant omission. Source: Internet