noumenon

the name given to a thing when it is viewed as a transcendent object. The term 'negative noumenon' refers only to the recognition of something which is not an object of sensible intuition, while 'positive noumenon' refers to the (quite mistaken) attempt to know such a thing as an empirical object. These two terms are sometimes used loosely as synonyms for 'transcendental object' and 'thing in itself', respectively. (Cf. phenomenon.)