SUBSTITUTIVITY

in this paper, i attempt a careful examination of the principle of substitutivity, sometimes referred to as 'leibniz' law', or 'leibniz' principle of identity of the indiscernibles'. after giving a precise and independent formulation of these three principles, i take issue with several alleged counterexamples to the principle of substitutivity and discuss, separately, the supposed failures of substitutivity attributable to the paradoxes of intensionality; difficulties involving the truth conditions of modal expressions and belief contexts. i contend that the alleged counterexamples hardly account for the meaning leibniz himself originally ascribed to the principle. furthermore, i shall argue that a restricted version of substitutivity may be true, and urge additional attempts to rescue this principle, under the conviction that an appropriate dismissal of the attacks on it, would give us better grounds to understand leibniz' claims on identity