Saul Kripke, R.I.P.

In 1959, a paper appeared in The Review of Symbolic Logic, with the unimpressive-sounding title 'A Completeness Theorem in Modal Logic.' A complete...

September 24, 2022
7:54 AM

In 1959, a paper appeared in The Review of Symbolic Logic, with the unimpressive-sounding title 'A Completeness Theorem in Modal Logic.' A completeness theorem is a guarantee that every universal truth—any statement that can't be false, no matter what—can be proved. In this case, these truths are about modality, about things that could or couldn't happen. You could've gone to the store to buy milk instead of to the bar to get a drink with friends, so we say getting the milk was possible. It couldn't have turned out that a circle isn't a circle, so we say in philosopher-talk that it's necessarily false.

Theodore Dalrymple