Thermodynamics is the science that describes much of the time asymmetric behavior found in the world. This entry's first task, consequently, is to show how thermodynamics treats temporally ‘directed’ behavior. It then concentrates on the following two questions. (1) What is the origin of the thermodynamic asymmetry in time? In a world possibly governed by time symmetric laws, how should we understand the time asymmetric laws of thermodynamics? (2) Does the thermodynamic time asymmetry explain the other temporal asymmetries? Does it (...) account, for instance, for the fact that we know more about the past than the future? The discussion thus divides between thermodynamics being an explanandum or explanans. In the former case the answer will be found in philosophy of physics; in the latter case it will be found in metaphysics, epistemology, and other fields, though in each case there will be blurring between the disciplines. (shrink)

Past entities, events, and circumstances are neither observable nor manipulatable. Several philosophers argued that this inaccessibility precludes a realistic conception of the past. I survey versions of antirealism and agnosticism about the past formulated by Michael Dummett, Leon Goldstein, and Derek Turner. These accounts differ in their motivations and reasoning, but they share the opinion that the reality of at least large swathes of the past is unknowable. Consequently, they consider statements about them as referring, at most, to present constructs. (...) These antirealists about the past are not, however, antirealists or skeptics about time or chronology. They accept, among other things, that present traces can be dated and statements about their temporal provenances are referring and truth-apt.I posit that an antirealist who accepts that at least some of the present traces can be truth-aptly dated while holding that these traces do not support knowledge about past events and circumstances commits herself to a radically skeptic stance. Otherwise, she would be diluting her position so that it will be hardly distinguishable from realism. This problem could be avoided if antirealists about the past would extend their antirealism to estimates of the age of present traces. Such a position, however, would imply a very drastic form of scientific antirealism. I conclude that the past’s inaccessibility is insufficient to support antirealism about the past, either as a part of moderate scientific antirealism or as a stand-alone position. (shrink)