Grazer Philosophische Studien

Volume 60, 2000

A Defense of Moderate Haecceitism

The identity of indiscernibles is false. Robert Adams and others have argued that if the identity of indiscernibles is false, then primitive thisness must be admitted as a fundamental feature of the world (i.e. haecceitism is true). Moreover, it has been suggested that if haecceitism is true, then essentialism is false - that accounting for individuation by means of haecceities precludes a thing's having essential qualitative properties. I will argue that this suggestion is misguided. In so doing, I will be defending what Adams has labeled 'moderate haecceitism'. After working through some preliminary issues, I will attempt (in section I) to motivate haecceitism. I will begin by reviewing Adams' arguments against the doctrine of the identity of indiscernibles. Next, I will examine altemative accounts of individuation which concede the falsity of that doctrine. I will reject these accounts and conclude that primitive thisness has an essential role to play in any satisfying account of individuation. In section II , I will surface the alleged tension between haecceitism and essentialism. In section III , I will suggest that Adams' moderate haecceitism avoids the tension surfaced in section II. Finally, in section IV, I will raise a difficulty for Adams' view and suggest a different understanding of the nature of haecceities. I will argue that the alleged tension between haecceitism and essentialism rests on a conflation of the metaphysical problem of individuation either with the epistemological problem which goes by the same name or with problems involving the unity of a thing. I will conclude with a few brief comments about the significance of moderate haecceitism for modal epistemology.