Huw Price

It has been suggested that some of the puzzles of QM are resolved if we allow that there is retrocausality in the quantum world. In particular, it has been claimed that this approach offers a path to a Lorentz-invariant explanation of Bell correlations, and other manifestations of quantum "nonlocality", without action-at-a-distance. Some writers have suggested that this proposal can be supported by an appeal to time-symmetry, claiming that if QM were made "more time-symmetric", retrocausality would be a natural consequence. Critics object that there is complete time-symmetry in classical physics, and yet no apparent retrocausality. Why should QM be any different? In this note I call attention to a respect in which QM is different, under some assumptions about quantum ontology. Under these assumptions, the option of time-symmetry without retrocausality is not available in QM, for reasons intimately connected with the fundamental differences between classical and quantum physics (especially the role of discreteness in the latter).

I once stood staring at a map in a large US airport, looking for an ATM. Next to me a couple also stared at the map, trying to figure out where in the airport they were. “Sheesh!” said the male at last, pointing to the red dot and the words ‘You are here’ in the key beside the map: “We’re way over here, right off the map!” Jenann Ismael’s understanding of red dots lies very much at the other extreme, but self-location – the task that couple were engaged in, however haplessly – is the unifying theme of The Situated Self. In Ismael’s hands, it is a thread that turns out to tie together a remarkable range of topics. Imagine being taken on a tour of your own home town, weaving in and out through various neighbourhoods, familiar and less so, and ducking between them via surprising paths and shortcuts. (“This next to that? Who knew!”) The Situated Self is that kind of book – an exhilarating and often demanding excursion, startling in its breadth and the ways it relates seemingly unconnected topics. Although the route of Ismael's tour is often highly original, the vehicle itself has a familiar shape, at least in outline. Ismael builds a chassis to specifications due especially to John Perry, fits it out to her own requirements, and then shows us where it can take us. Mostly, I found the excursion convincing, as well as fascinating. In what follows, I shall take up one case in which I was not convinced, and then raise an issue about another destination – somewhere in the same vicinity, apparently – and ask whether Ismael’s bus takes us there, too. First, though, to the fundamentals, as Ismael develops them

Pragmatists recommend that in approaching a problematic concept in philosophy, we should begin by examining the role it plays in the practical, cognitive and linguistic lives of the creatures who use it. This paper stems from an interest in pragmatic accounts, in this sense, of the various modal notions we encounter in science. I propose that pragmatists about these notions should avail themselves of the vocabulary of theoretical models. This vocabulary brings to the foreground the issues of function, use and role in practice, on which pragmatists want to focus; while downplaying the naive representationalism that pragmatists see as an impediment to good philosophy. I show how this framework may be used to delineate a kind of pragmatic perspectivalism about probability, and argue that the same template offers a promising way to make sense of the link between causation and manipulability.

In this paper we defend the view that the ordinary notions of cause and effect have a direct and essential connection with our ability to intervene in the world as agents.1 This is a well known but rather unpopular philosophical approach to causation, often called the manipulability theory. In the interests of brevity and accuracy, we prefer to call it the agency theory.2 Thus the central thesis of an agency account of causation is something like this: an event A is a cause of a distinct event B just in case bringing about the occurrence of A would be an effective means by which a free agent could bring about the occurrence of B. In our view the unpopularity of the agency approach to causation may be traced to two factors. The first is a failure to appreciate certain distinctive advantages that this approach has over its various rivals. We have drawn attention to some of these advantages elsewhere, and we summarize below. However, the second and more important factor is the influence of a number of stock objections, objections that seem to have persuaded many philosophers that agency accounts face insuperable obstacles. In this paper we want to show that these objections have been vastly overrated. There are four main objections