noumenon
n. (pl.
noumena) in the philosophy of Immanuel Kant, a thing in itself as contrasted with a thing known through the senses and human understanding (see phenomenon). Although the noumena are the causes of one’s experience, they can never themselves be experienced, as they lie outside time and space; nor can they be apprehended by speculative reason, because the general concepts of quantity, quality, relation, and so forth apply only to phenomena. The ideas of God, freedom, and immortality belong to the noumenal realm but are accessible to human beings through their experience as moral agents. —noumenal
adj.