necessary condition
logic
Quick Summary
In logic, a necessary condition is something that must be true or exist for another thing to occur. It's a prerequisite. For example, a severed spinal column is a necessary condition for death, though not a sufficient one.12
A proposition is considered logically necessary if it aligns with a law of logic or can be made to do so through equivalent substitutions. These necessary propositions are true in all possible worlds. In contrast, a contingent proposition is true in some possible worlds and false in others.3
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