necessary condition
Must have first
A necessary condition is something that must be present or true for a particular outcome to occur, though it alone may not guarantee that outcome.
Oxygen is a necessary condition for fire—no fire can exist without it—but oxygen alone doesn't cause fire.
Contrast with sufficient condition, which guarantees an outcome by itself.
Citizenship is a necessary condition for voting, but not sufficient—you must also register.
- preconditionNecessary prior requirement
- sine qua nonIndispensable condition
- prerequisiteRequired prior condition
- first things firstBegin with essentials
- antecedentSomething that precedes
counterfactuals · indispensable · deal breaker · causality · start · logical consequence · effect · key · essential element · foundation · ground floor · presupposition · entry ticket · bare minimum · trigger · base · dependent · if-then
- logic rulessyllogism, inference, contraposition, double negation, conjunction
- logicpremise, premises, conclusion, conclusions, inference
- proofsproof by contradiction, contrapositive, contradiction, theorem, lemma
condition, necessary, necessity, unnecessary, conditional, necessitate, necessitated, necessitating, necessitates