Philosophy - any fact assumed to be a matter of direct observation or any proposition assumed or given, from which conclusions may be drawn. Epistemology - also called 'sense datum', the object of knowledge as presented to the mind, in contrast to ideatum.

Source: datum. Dictionary.com. Dictionary.com Unabridged (v 1.1). Random House, Inc. http://dictionary.reference.com/browse/datum (accessed: February 18, 2007).