L. Nathan Oaklander
The problems of time and change are inextricably connected for change involves time and, Shoemaker (1969) notwithstanding, time involves change, or so McTaggart (1934; 1968) has argued. That they are related is not in doubt; how they are related is. For McTaggart they are related in such a way that if there is to be time and change, then there must be an A-series, and temporal becoming, but what is the A-series? And what is temporal becoming? These are not easy questions to answer, because there are many different versions of A-time and temporal becoming, and I do not intend to discuss them all. Rather, my aim will be to focus on one version of A-time, the presentist version, and argue that, contrary to its recent proponents, it does succumb to McTaggart's paradox. 1 Even within the limited scope of this chapter, the task of refuting presentism is complicated by there being several different versions of it. One would not think that this is so because all presentists maintain that only the present exists, whereas the past and the future do not exist. Nevertheless, there are different presentist versions of the A-theory, and, although I believe that in one way or another they are all susceptible to McTaggart's paradox, there is only one version that I shall endeavour to refute, namely that propounded by William Lane Craig in his recent trilogy on time: The Tensed Theory of Time: A Critical Examination (2000a), The Tenseless Theory of Time: A Critical Examination (2000b) and Time and the Metaphysics of Relativity (2001).
I chose Craig's defence of presentism for two reasons. First, A-theorists who follow Prior in adopting a presentist 'metaphysic' are often criticized for lacking an ontology (see, for example, Oaklander 1984:90-2; Smith 1993:158-69; 1994a; 1999:248-9; 2003; Tooley 1997:165-70, 232-8). To say that the tenses do not refer to B-relations and do not ascribe A-properties is one thing, to say what then are the ontological correlates of the tenses is quite another. It is the latter task that Prior and his followers are commonly accused of shirking. Craig is an exception. He is sensitive to the 'lack of ontology' criticism of Prior-based theories (see Craig 2000a: 192-4), and attempts to 'found' or provide an ontological ground for both B-relations and A-determinations in the A-series, 'tensed facts' and temporal becoming. For that reason, he provides his readers with a metaphysical theory to be evaluated.