The philosophy of time contains a debate that the philosophy of space lacks, namely whether one time, the present, is objectively (i.e. mind-independently) unlike all the others. Whether reality itself is tensed, i.e. whether position in time has ontological significance, is a long-standing but still pressing question. This book defends a unified account of the structure of time and our representations of it, arguing that while the universe itself is not centred on any particular time, we can nevertheless explain why (...) we so commonly think and act as if it is. In other words, a version of the B-theory of time is defended. It is argued, first, that eternalism—the view that all times are equally real—is the proper ontology of time. Then a semantics of tensed language and belief is presented that is entirely tenseless, hence compatible with eternalism. Next, it is argued that temporal predicates express relations between ordinary, three-dimensional objects, and times; accordingly, there is no need to posit the existence of temporal parts. Finally, it is argued that the B-theory provides an adequate account of change, persistence, and temporal passage. (shrink)

Ian Hacking’s wide-ranging and penetrating analysis of science contains two well-developed lines of thought. The first emphasizes the contingent history of our inquiries into nature, focusing on the various ways in which our concepts and styles of reasoning evolve through time, how their current application is constrained by the conditions under which they arose, and how they might have evolved differently. The second is the mistrust of the idea that the world contains mind-independent natural kinds, preferring nominalism to ‘inherent structurism’. (...) These two pillars of thought seem at first to be mutually reinforcing: the lack of natural structure can help make sense of scientific variability and revision, while variability and revision provide reason to suspect that natural structure is little more than idealization. In what follows, I argue that these two pillars not only fail to support each other, but in fact conflict. One of them must fall, and it is clear which. (shrink)