Intuition and the Substitution Argument

摘要: Superman has a bad allergy to kryptonite. And since is Clark Kent, it follows that Kent allergic Which, indeed, he is. If you were take some kryponite into the offices of Daily Planet, would soon be feeling quite poorly. Of course, not many people know In particular, Superman’s nemesis Lex Luthor does kryptonite, which why sneak newsroom and hide kryptonite in Clark’s desk. But knows perfectly well frequently tries expose him it. That, at least, sort thing one usually hear say. Familiarly, however, taking such remarks face value generates problems. The most immediate these requires us restrict logical principle known as “substitution identicals”: