Neo-Aristotelian mereology

Abstract

In her book The Structure of Objects, Kathrin Koslicki develops and defends a neoAristotelian theory of objects, according to which objects are structured wholes that exist only if their parts are adequately unified and exhibit the right kind of structure. In Chaps. 1–3 Koslicki outlines classical extensional mereology and criticises the widely held view that objects are to be understood as mereological sums that obey the unrestricted fusion axiom. She also puts forward a Leibniz’s Law-style argument against the view that composition counts as a form of identity, showing that various ways of restricting the applicability of Leibniz’s Law are suspect. Chapter 4 contains a description and critique of Kit Fine’s theory of rigid and variable embodiments, the most detailed contemporary statement of a neo-Aristotelian view of composition. While Koslicki agrees with Fine’s arguments against standard mereology, she criticises Fine’s positive account on the basis that it leads to a proliferation of different parthood relations and commits us to an overabundance of objects. Chapters 5 and 6 are historical investigations of Plato’s and Aristotle’s views about parts and wholes, which have inspired Koslicki’s own approach. In Chaps. 7–9 Koslicki sets out her positive proposal for a structure-based mereology and provides detailed discussions of natural kinds and of the notion of structure. The key features of Koslicki’s view are that (i) composition is restricted, that (ii) there is a form/matter dichotomy, that (iii) composition fails to be ontologically innocent, and that (iv) wholes are unified. (i) Restricted composition. Koslicki holds that not every collection of objects composes a further object, but only those collections that are adequately unified and exhibit the right kind of structure. Composition only takes place when parts are related in such a way as to satisfy the conditions for composing an object of a particular kind. Which composite objects exist is accordingly fixed by what kinds