Łukasiewicz, the sea battle, and why three-valued logic was born in Lwów
In De Interpretatione 9 Aristotle considers the sentence "there will be a sea battle tomorrow". If it is already true today, isn't the battle already necessary? And if so, isn't deliberation pointless?
Around 1920 Jan Łukasiewicz, working in the Lwów–Warsaw school founded by Twardowski, introduced a third truth value, often glossed as "possible", for statements like this. His motivation was explicitly philosophical: he wanted to protect indeterminism and freedom.
Modern approaches mostly prefer supervaluationism (Thomason, 1970). "Either there will be a sea battle or there won't" comes out true, though neither disjunct is yet true, which is one way to keep classical logic for compound statements.
What I'd like to discuss: did Aristotle himself deny bivalence for future contingents, or only that their truth is necessary? The text supports both readings depending on how you translate a few lines.