Marcus Ackermann

The principle of the fixity of the past says that nobody is able to act in a way such that the past would have been different. The aim of this paper is to cast epistemic doubt on this principle. I do so by advancing two kinds of debunking arguments—arguments that purport to undermine our rational confidence in a given belief by pointing out its epistemically infelicitous origins—against it that, taken together, form a debunking dilemma. If our intuition that the past is fixed traces back to belief in (and/or purported experience of) temporal passage, then the fixity of the past is more likely than hitherto appreciated to be false. But if it doesn’t, then the fixity of the past is less likely than so far assumed to be true. Either way, Bayesian reasoning will demand a reduction of our current credence in this principle. Importantly, however, my argument stops short of mandating an outright rejection of the fixity of the past.

Limited foreknowledge open theism (LFOT) is the view that there are contingent truths about the future but that even an omniscient God cannot foreknow them. This paper mounts a three-pronged philosophical defence of this doctrine. On the one hand, I will show that it can be given a formal model and semantics that is both _formally_ and _descriptively_ adequate. In doing so, I draw heavily on the most recent advancements in Thin Red Line semantics, and ultimately recommend a framework that combines familiar formal elements in a novel way: this places LFOT on a solid logical foundation. On the other hand, I will show that the two most prominent objections to LFOT, namely Todd’s (Philosophia 42(2):523–538, 2014) _grounding objection_ and Arbour's (Int J Philos Relig 73:189–207, 2013) _fatalistic objection_, can both be met. With respect to the former, we will see that the proponent of LFOT is (_pace_ Todd) able to heed a suitable grounding requirement for future contingent truths. And as regards the latter, it will be demonstrated (_pace_ Arbour) that LFOT does not entail logical fatalism. The upshot of this is that LFOT is, at least from a philosophical perspective, perfectly plausible.