that all objects are dependent upon designation, and therefore any discussion regarding the nature of objects can only be made in light of the context. The validity of objects can only be established within those conventions that assert them. Facts Bertrand Russell updated the classical terminology with one more term, the fact; "Everything that there is in the world I call a fact." Facts, objects, are opposed to beliefs, which are "subjective" and may be errors on the part of the subject, the knower who is their source and who is certain of himself and little else. All doubt implies the possibility of error and therefore admits the distinction between subjectivity and objectivity. The knower is limited in ability to tell fact from belief, false from true objects and engages in reality testing, an activity that will result in more or less certainty regarding the reality of the object. According to Russell, "we need a description of the fact which would make a given belief true" where "Truth is a property of beliefs." Knowledge is "true beliefs". Applications Value theory Value theory concerns the value of objects. When it concerns economic value, it generally deals with physical objects. However, when concerning philosophic or ethic value, an object may be both a physical object and an abstract object (e.g. an action). Physics Limiting discussions of objecthood to the realm of physical objects may simplify them. However, defining physical objects in terms of fundamental particles (e.g. quarks) leaves open the question of what is the nature of a fundamental particle and thus asks what categories of being can be used to explain physical objects. Semantics Symbols represent objects; how they do so, the map–territory relation, is the basic problem of semantics. See also Abstract object theory Abstraction Category theory Continuous predicate Concept Hypostatic abstraction Hypostasis (philosophy and religion) Noumenon and phenomenon Objectivity (philosophy) Observer (physics) Sign relation Ship of Theseus Object-oriented ontology Subject (grammar) Subject (philosophy) Nonexistent object References Sources External links Concepts in epistemology Concepts in metaphysics Dichotomies Ontology Physical objects