Dictionary:

noumenon

  (nū'mə-nŏn')

In the philosophy of Kant, an object as it is in itself independent of the mind, as opposed to a phenomenon. Also called thing-in-itself.

[German, from Greek nooumenon, from neuter present passive participle of noein, to perceive by thought, from nous, mind.]

A term especially associated with Kant, denoting things as they are in themselves, as opposed to things as they are for us, knowable by the senses (phenomena). The noumenal lies behind the mind-imposed forms of time, space, and causation, and is therefore unknowable. On one view Kant is locked into a ‘two-worlds’ view, so that the noumenal is rather like Berkeley's God, in being responsible for the phenomenal world, except that we cannot know anything of its nature. On a different view, the distinction merely reflects Kant's understanding that all knowledge is knowledge from a standpoint, so the noumenal is the fraudulent idea of that which would be apprehended by a being with no point of view. It is unclear how on Kant's own view we can mean anything by the term, but Kant does suppose that we need to postulate a noumenal reality and especially a noumenal self as a condition of human free will, the phenomenal self being all too determined in its actions.

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 be a process of reasoning -- which is a phenomenon. Nevertheless, the discovery and exposition of noumena offer a rich field for what Lewes calls "the endless variety and excitement of philosophic thought." Hurrah (therefore) for the noumenon!