Mally Introduces First Formal Deontic System

In 1926, Ernst Mally proposed the first formal deontic logic in The Basic Laws of Ought, presenting a propositional calculus extended with a unary obligation connective (!) and binary operators (f, ∞) plus five deontic axioms. The system yields controversial consequences—most notably 'A is obligatory iff A is the case'—which critics like Menger rejected; the article analyzes Mally’s terminology, axioms, and possible formal repairs.