Sara Bernstein

Suppose that Billy and Suzy each throw a rock at window, and either rock is sufficient to shatter the window. While some consider this a paradigmatic case of causal overdetermination, in which multiple cases are sufficient for an outcome, others consider it a case of joint causation, in which multiple causes are necessary to bring about an effect. Some hold that every case of overdetermination is a case of joint causation underdescribed: at a maximal level of description, every cause is necessary to bring about the outcome in precisely the way that it occurs. -/- This paper shows the latter principle to be false. I introduce a novel class of events that are insensitive to the additive force of multiple causes. They are to be contrasted with sensitive events, which physically and counterfactually vary according to the number and sorts of causes they have. I argue that sensitive effects are symptoms of joint causation; insensitive effects are symptoms of overdetermination. Insensitive effects resulting from multiple causes cannot be classified as "joint causation underdescribed," but only as overdetermination. -/- I suggest that cases of "trumping preemption" should be understood as cases of overdetermination with insensitive effects. Consequently, Lewis' influence account of causation cannot handle these cases.

Widespread causal overdetermination is often levied as an objection to nonreductive theories of minds and objects. In response, nonreductive metaphysicians have argued that the type of overdetermination generated by their theories is different from the sorts of coincidental cases involving multiple rock-throwers, and thus not problematic. This paper pushes back. I argue that attention to differences between types of overdetermination discharges very few explanatory burdens, and that overdetermination is a bigger problem for the nonreductive metaphysician than previously thought.

This paper suggests that time travelling scenarios commonly depicted in science fiction introduce problems and dangers for the time traveller. If time travel takes time, then time travellers risk collision with past objects, relocation to distant parts of the universe, and time travel-specific injuries. I propose several models of time travel that avoid the dangers and risks of time travel taking time, and that introduce new questions about the relationship between time travel and spatial location.

Free will, if such there be, involves free choosing: the ability to mentally choose an outcome, where the outcome is 'free' in being, in some substantive sense, up to the agent of the choice. As such, it is clear that the questions of how to understand free will and mental causation are connected, for events of seemingly free choosing are mental events that appear to be efficacious vis-a-vis other mental events as well as physical events. Nonetheless, the free will and mental causation debates have proceeded largely independently of each other. Here we aim to make progress in determining how the free will and mental causation debates bear on one another. We first argue that the problems of free will and of mental causation can be seen as special cases of a more general problem, concerning whether and how mental events of a given type may be efficacious, qua the types of event they are---qualitative, intentional, freely deliberative---given their apparent causal irrelevancy for effects of the type in question; here we generalize what Horgan 1989 identifies as "the problem of mental quausation" (S1). We then build on this result to identify fruitful parallels between hard determinism and eliminative physicalism (S2) and soft determinism and non-reductive physicalism (S3).