Dust you are and unto dust you shall return

Dust you are and unto dust you shall return. A material object is constituted by a sum of parts all of which are essential to the sum but some of which seem inessential to the object itself. Such object/sum of parts pairs include my body/its torso and appendages and my desk/its top, drawers, and legs. In these instances, we are dealing with objects and their components. But, fundamentally, we may also speak, as Locke does, of an object and its constitutive matter—a " mass of particles " —or even of that aggregate and the sum of subatomic particles 'making it up'. The " problem of material constitution " (henceforth, PMC) is generated by assuming inter alia that the members of any such pair are numerically identical, that is, that the constituted and the constituting are one and the same thing. 1 This assumption—that constitution entails identity (henceforth, CA)— makes for cases in which supposedly identical things differ as to their essential features: for example, it seems that my desk could have one of its parts replaced without ceasing to exist, unlike the sum of its components or its constitutive matter. 2 I shall attempt here to preserve CA, which underlies the way in which we count, as well as an ontology consisting of " commonsense " continuants: objects capable of surviving mereological modification (such as, tables, trees, and tigers). I, therefore, not only defend CA, but also provide an account of how it is possible for an object to change the sum/aggregate of parts to which it is identical. The resulting dualistic conception of identity ultimately requires me to refine the principle of the Transitivity of Identity (TI). The concept formed when " considering anything as existing at another time, " as Locke characterizes judgments of diachronic identity, is to be regarded as our " popular " understanding of identity, defining the relationship holding between (e.g.) the present author and a certain boy but not between that boy and Winston Churchill. It is this notion that entails the existence of the mereologically alterable, such as the boy who was to be the present author. In contrast with it, there is the " strict " sense in which things may be identical, CA, which makes for ontological parsimoniousness and, thus, entails our standard counting procedure: we do not tally as two a sum or aggregate of parts and that which it …