Abstract

Some theories in the philosophy of time combine a commitment to the existence of non-present regions of spacetime with the view that there is a perspective-independent present time. We call such theories 4D A-theories. There is a well-known objection to 4D A-theories, as follows: 4D A-theories entail that the vast majority of subjects across time believe falsely that they are present. But if the vast majority of subjects across time believe falsely that they are present, we do not know that we are present. We call this the Epistemic Objection to 4D A-theories. In this paper we do two things: first, we describe and assess a number of different versions of the Epistemic Objection. We argue that there is only one version of the objection—the version due to Russell that we call the Safety Argument—that does not rely on implausible epistemic principles which entail radical scepticism. Second, we raise objections to the main strategies adopted by 4D A-theorists in response to the Safety Argument. We conclude that the Epistemic Objection—in the form of the Safety Argument—remains a threat to 4D A-theories.