Why are logically true propositions true in every possible scenario?

In logic, a proposition is considered logically true if it is necessarily true, meaning it cannot be false under any circumstances. The reason these propositions hold true in every possible scenario—or every possible world—is rooted in their structure and definition rather than empirical facts about the world.12

Logically true propositions are often categorized as analytic propositions, which are statements whose truth is guaranteed by the principle of contradiction; denying them would result in a self-contradiction. In the propositional calculus, such statements are known as tautologies. These are formulas that remain true regardless of the truth-values assigned to their individual variables, a fact that can be demonstrated mechanically using a truth table.342

Because these truths are derived from the rules of language, definitions, or fundamental logical laws, they do not depend on how the actual world is configured. Consequently, they maintain their truth-value across all possible scenarios, as they do not assert anything about contingent facts, but rather elucidate meanings or formal structures that are inherently necessary.214