Selvkonsistente

Selvkonsistente is a term used in Scandinavian languages to describe a system, theory, model, or set of statements that is internally coherent and free from contradictions. The essential idea is that the various components of the description support each other under a common framework, and no part implies something that contradicts another part.

In logic and philosophy, self-consistency distinguishes a theory from one that contains contradictory claims. A self-consistent theory does not prove both a proposition and its negation. However, it is possible for a theory to be consistent without being complete, a point highlighted by Gödel’s incompleteness theorems. In discussions of knowledge and belief, self-consistency is often treated alongside coherence as a measure of how well its elements fit together.

In science and mathematics, self-consistency takes several forms. The self-consistent field (SCF) method in quantum chemistry is an iterative approach where the electronic structure is solved so that the orbitals and the potential they generate are mutually compatible. In physics and cosmology, the Novikov self-consistency principle posits that any action taken by a time traveler along a closed timelike curve must be self-consistent with the history that would appear to them, preventing paradoxes.

In data modeling and software, self-consistency refers to invariants that must hold across the system, such as databases maintaining coherent state and operations that do not violate defined constraints. The term is often used more broadly to indicate that a constructed description, whether mathematical, empirical, or conceptual, does not contain internal contradictions and aligns with its stated assumptions.

See also: consistency, coherence, self-reference, Novikov principle, self-consistent field.