Presentism and Ontological Symmetry

PRESENTISM AND ONTOLOGICAL SYMMETRY Joseph Diekemper Introduction Presentism tells us that since only the present exists, the past and future are equally unreal. But presentism is also motivated, just as any A-Theory of time is, by the common sense intuition that the past is fixed and the future not. It is, in part, this belief in a robust asymmetry of fixity that makes the A-Theory distinctive. But are these two doctrines— that of ontological symmetry and asymmetry of fixity—compatible, or do they represent inconsistencies in the presentist’s theory? In this paper, I will argue that there is indeed an inconsistency between the two doctrines, and that the presentist is unable to account for the temporal asymmetry that is so fundamentally a part of her theory. In Section I, I will briefly outline a recent defense of presentism due to Craig. In the course of this defense, Craig attempts to draw out the analogy between modal actualism, on the one hand, and presentism, on the other, by formulating a tensed possible worlds semantics on the model of the tenseless possible worlds semantics endorsed by the modal actualist. I will argue that Craig’s tensed semantics, which I will refer to as actualist presentism (AP), are not strictly analogous to the tenseless ones, and that this disanalogy highlights the tension between the presentist’s doctrines of ontological symmetry and asymmetry of fixity. In Section II, I will undertake an investigation, on the presentist’s behalf, in order to determine whether she is capable of reconciling these two doctrines. The investigation, based on a suggestion from Craig, will involve considering different asymmetries, other than that of ontology, which might be said fundamentally to constitute