Arthur Prior

New Zealand logician who founded tense logic — modal logic for time — and contributed to the philosophy of time and ethics.

Tense logic: a formal logic with operators for 'it will be the case that' and 'it was the case that' — the foundational framework for all temporal reasoning in computer science, artificial intelligence, and philosophy. Time and Modality: tense operators are genuine logical operators, not mere descriptions of temporal position. Thank Goodness That's Over: argued that the A-series is real — the relief we feel when something is over cannot be captured by the B-series.