Philosophy
The Logic of Modal Operators and Deontic Logic
Quick fact
Deontic logic treats 'must' and 'ought' as modal operators, just like 'necessarily' and 'possibly,' and this allows philosophers to analyze moral rules using the same rigorous framework as mathematics.
Why this is interesting
We often say 'it must be true' or 'you ought to do this.' But what do these statements really mean? Logic has a precise way to model such necessity and obligation.