Logic

  • ‘Just in case’: if and only if?
    ,

    ‘Just in case’: if and only if?

    The prevailing view in North American philosophical writing seems to be that the phrase ‘just in case’ can be translated into the phrase ‘if and only if’. Consequently, this view holds that the phrase ‘just in case’ is best symbolized by the logical connective known as the biconditional (↔). Now, this seems wrong to me…

  • I’ll die if I’m immortal, or I’ll live if I die: the material conditional vs. if/then

    Here’s a tautology in propositional logic: ⊨(P → Q) ∨ (Q → R) Try throwing that into English. Here’s a reading using some propositions I just came up with: “I’ll die if I’m immortal, or I’ll live if I die.” Obviously, neither of those are the case. But this formula, (P → Q) ∨ (Q…