Editing Logical atomism (section)

=== Russell's principles ===

Bertrand Russell's theory of logical atomism consists of three interworking parts: the atomic proposition, the [[atomic fact]], and the atomic complex. An atomic proposition, also known as an elemental judgement, is a fundamental [[Statement (logic)|statement]] describing a single entity. Russell refers to this entity as an atomic fact, and recognizes a range of elements within each fact that he refers to as [[particular]]s and [[universal (metaphysics)|universal]]s. A particular denotes a signifier such as a name, many of which may apply to a single atomic fact, while a universal lends quality to these particulars, e.g. color, shape, disposition. In Russell's [[Knowledge by acquaintance|Theory of Acquaintance]], awareness and thereby knowledge of these particulars and universals comes through [[sense data]]. Every system consists of many atomic propositions and their corresponding atomic facts, known together as an atomic complex. In respect to the nomenclature that Russell used for his theory, these complexes are also known as molecular facts in that they possess multiple atoms. Rather than decoding the complex in a top-down manner, logical atomism analyzes its propositions individually before considering their collective effect. According to Russell, the atomic complex is a product of human thought and ideation that combines the various atomic facts in a logical manner.

Russell's perspective on belief proved a point of contention between him and Wittgenstein, causing it to shift throughout his career. In logical atomism, belief is a complex that possesses both true and untrue propositions. Initially, Russell plotted belief as the special relationship between a subject and a complex proposition. Later, he amended this to say that belief lacks a proposition, and instead associates with universals and particulars directly. Here, the link between psychological experience – sense data – and components of logical atomism – universals and particulars – causes a breach in the typical logic of the theory; Russell's logical atomism is in some respects defined by the crossover of metaphysics and analytical philosophy, which characterizes the field of [[naturalized epistemology]].<ref>{{Cite journal|title = Bertrand Russell's Flirtation with Behaviorism|last = Kitchener|first = Richard F.|date = 2004|journal = Behaviorism and Philosophy}}</ref>

In his theory of Logical Atomism, Russell posited the highly controversial idea that for every positive fact exists a parallel negative fact: a fact that is untrue. The [[Correspondence theory of truth|correspondence theory]] maintains that every atomic proposition coordinates with exactly one atomic fact, and that all atomic facts exist. The Theory of Acquaintance says that for any given statement taking the form of an atomic proposition, we must be familiar with the assertion it makes. For example, in the positive statement, "the leaf is green," we must be acquainted with the atomic fact that the leaf is green, and we know that this statement corresponds to exactly this one fact. Along this same line, the complementary negative statement, "the leaf is not green," is clearly false given what we know about the color of the leaf, but our ability to form a statement of this nature means that a corresponding fact must exist. Regardless of whether the second statement is or isn't true, the connection between its proposition and a fact must itself be true. One central doctrine of Logical Atomism, known as the Logically Perfect Language Principle, enables this conclusion. This principle establishes that everything exists as atomic proposition and fact, and that all language signifies reality.  In Russell's viewpoint, this necessitates the negative fact, whereas Wittgenstein maintained the more conventional [[Principle of Bivalence]], in which the states "P" and "Not (P)" cannot coexist.