NOUMENON, 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!
-- Ambrose Bierce, "The Devil's Dictionary"
