THE GENEALOGY OF 'V'

The use of the symbol boolean OR for disjunction in formal logic is ubiquitous. Where did it come from? The paper details the evolution of the symbol boolean OR in its historical and logical context. Some sources say that disjunction in its use as connecting propositions or formulas was introduced by Peano; others suggest that it originated as an abbreviation of the Latin word for "or," vel. We showthat the origin of the symbol boolean OR for disjunction can be traced toWhitehead and Russell's pre-Principia work in formal logic. Because of Principia's influence, its notation was widely adopted by philosophers working in logic (the logical empiricists in the 1920s and 1930s, especially Carnap and early Quine). Hilbert's adoption of boolean OR in his Grundzuge der theoretischen Logik guaranteed its widespread use by mathematical logicians. The origins of other logical symbols are also discussed.