Definition
An element of the range of semantic evaluation assigned to a proposition or formula; in classical logic the canonical truth values are True and False (bivalence), while other systems may admit additional or partial values.
Principle
Principle
A truth value is what a valuation assigns to a well-formed formula under a given interpretation; logical operations and semantic clauses specify how complex formulas obtain truth values from those of their parts.
Demonstration
Demonstration
Under a standard valuation, the sentence 'Snow is white' receives the truth value True if in the relevant interpretation snow is white; in three-valued logic a sentence might receive an intermediate value such as 'undetermined'.
Misapplication
Misapplication
Confusing truth value with degree of belief or probability, treating it as a pragmatic property (assertability) rather than a semantic assignment, or reifying it as an ontological property of a sentence are common errors.
Consequence
Consequence
Truth values provide the basis for semantic notions such as tautology, contradiction, satisfiability, and entailment; they enable mechanical model checking and rigorous semantic comparison of formulas.
Reversal
Reversal
Rejecting bivalence yields truth-value gaps (neither true nor false) or truth-value gluts (both true and false) in nonclassical logics, which reverses many classical inference patterns and requires revised semantic rules.
Boundary
Boundary
The term refers to semantic evaluation within a specified logic and interpretation; it does not by itself settle metaphysical questions about truth, nor is it equivalent to probability, justification, or pragmatic acceptability.
Semantic Tension
Semantic Tension
There is tension between the simplicity of two-valued truth evaluations and richer frameworks (many-valued, supervaluationist, paraconsistent) that aim to model vagueness, indeterminacy, or paradox; choosing a scheme affects which inferences hold.
Synthesis
Synthesis
A truth value is the semantic tag assigned to a formula by a valuation within a specified logical framework; as the primitive outcome of semantic evaluation it structures notions of validity and equivalence while varying across logical systems.