or perdurance theory is a philosophical theory of persistence and identity
. The perdurantist view is often defined as being the claim that objects have distinct temporal parts
as opposed to endurantism
(endurantism is the view that an individual is wholly present at every moment of its existence). The use of "endure" and "perdure" to distinguish two ways in which an object can be thought to persist can be traced to David Kellogg Lewis
(1986). However, contemporary debate has demonstrated the difficulties in defining perdurantism (and also endurantism). For instance, the work of Ted Sider
(2001) has suggested that even enduring objects can have temporal parts, and it is more accurate to define perdurantism as being the claim that objects have a temporal part at every instant that they exist. Zimmerman (1996) has said that this won't work, as there have been many self-professed perdurantists who believe that time is 'gunky' and that for every interval of time, there is a sub-interval. Consequently there are no instants, and Sider's definition must be altered to admit of this fact. Currently there is no universally acknowledged definition of perdurantism (see also McKinnon (2002) and Merricks (1999)).
Worm theorists and stage theorists
Perdurantists break into two distinct sub-groups. The former are 'worm theorists'. They believe that a persisting object is composed of the various temporal parts that it has. So all persisting objects are four-dimensional 'worms' that stretch across space-time, and that you are mistaken in believing that chairs, mountains and people are actually three-dimensional. This is to be contrasted to a more recent twist called 'stage theory'. Stage theorists take you to be identical with a particular temporal part at any given time. So, in a manner of speaking, I only exist for an instantaneous period of time. However there are other temporal parts at other times which I am related to in a certain way (Sider talks of 'modal counterpart relations', whilst Hawley talks of 'non-Humean relations') such that when I say that I was a child, or that I will be an OAP, these things are true because I am related to a temporal part that is a child (that exists in the past) or a temporal part that is an OAP (that exists in the future). Stage theorists are sometimes called 'exdurantists'.
Reasons to be a perdurantist
There are many reasons on offer to become a perdurantist, ranging from problems in logic, to the problem of temporary intrinsics, to the problems of the Ship of Theseus. An excellent survey can be found in Sider (2001).
- Temporal parts - Stanford Encyclopedia of Philosophy
- Lewis, D.K. 1986. On the Plurality of Worlds Oxford: Blackwell
- McKinnon, N. 2002. "The Endurance/Perdurance Distinction", The Australasian Journal of Philosophy 80:3 p. 288-306.
- Merricks, T. 1999. "Persistence, Parts and Presentism", Nous 33 p. 421-38.
- Sider, T. 2001. Four-Dimensionalism Oxford: Clarendon Press.
- Zimmerman, D. 1996. "Persistence and Presentism", Philosophical Papers 25: 2.