Michael Kump

This dissertation was submitted and accepted in 1979 for the degree of Doctor of Philosophy (Philosophy) at The University of Michigan in Ann Arbor. The Doctoral Committee included Professor Jaegwon Kim (Co-Chairman), Assistant Professor Timothy G. McCarthy (Co-Chairman), and Assistant Professor Louis E. Loeb. This dissertation undertakes a metaphysical examination of our concept of a physical object’s persistence through time. Certainly, the concept of a persisting physical object is at the core of our ordinary ways of thinking about the world. The philosopher’s challenge is to see if anything broad and systematic can be said about such a concept. When inquiring into an object’s persistence through time, we are asking for a characterization of the unity of a physical object’s history. The object’s history stretches over temporal intervals, and objects can be viewed as being temporally elongated entities. As such, a way of talking about objects persisting at different times must be developed. A central feature in this enterprise will be the notion of an object-stage which can be defined as follows: Object-stage =df. The material content of the space-time region occupied at a time. An object’s history, comprised out of a succession of object-stages, must fit together in some fashion or other. However, it is obvious that not just any succession of object-stages constitutes the history of a single persisting object. Since not just any succession of stages will suffice, the task becomes one of trying to determine what the special relationship is between successive stages which do correspond to the history of a single object. Hence, the central problems of this dissertation can be delineated accordingly: (a) when is a succession of object-stages, object-stages in the history of a single physical object?; and, (b) under what conditions is a physical object which exists at one time the same object as (or, identical with) a physical object which exists at another time? My analysis of the persistence of physical objects is presented in Chapter IV. It turns out that the analysis is complex, a necessity when the broad range of results to be accounted for is recognized. This task is undertaken in Chapters II and III. In the former Chapter, I argue that prior to the construction of an analysis of persistence, we must recognize certain pre-theoretic “data” concerning objects and their persistence. Chapter II ponders a variety of cases, employing arguments to draw out consequences which our analysis must account for. After Chapter II has delineated those results which must be incorporated in the analysis, Chapter III reviews various attempts to provide an account of persistence. However, it is argued that all such attempts fail to adequately account for the results set out in Chapter II. Chapters V through VIII investigate a wide spectrum of issues in contemporary metaphysics checking to see how my analysis illuminates these problems. Chapters V and VI study the necessity of origins thesis. As a result of that study, a certain range of properties are specified as being original essential properties of an object. Chapter VII takes up the troublesome topic of transworld identity, closely associated with the problem of essentialism. A solution to this issue is suggested which utilizes my analysis of persistence and the views of many other philosophers. The final Chapter considers the debate over relative and absolute identity. It is demonstrated that my analysis of persistence is neutral with respect to this controversy, and in that Chapter my analysis is accommodated to either theory of identity.