Notre Dame Journal of Formal Logic · 1963 · 91 citations · 0 references
HumanitiesPhilosophyExistentialismLogicSemanticsDeductive ReasoningNon-classical LogicPredicate LogicExistential TypesGeneralized QuantifiersNull SemanticsSymbolic Logic
The traditional logic supposed statements of the form (x) Fx D Gx 9 to have existential import, and so licensed the inference from '(x) Fx JGx 9 to '(3 x) Fx Gx 9 . But let 9 be 'a brakeless car' (or 'is a unicorn'), and 'G' be 'is dangerous' (or 'is a unicorn'). Then the false statement that there exists a brakeless car (or that there exists a unicorn) can be inferred.