This paper considers the possibility that nonrelativistic quantum mechanics tells us that Nature cares about time reversal. In a classical world we have a fundamentally reversible world that appears irreversible at higher levels, e.g., the thermodynamic level. But in a quantum world we see, if I am correct, a fundamentally irreversible world that appears reversible at higher levels, e.g., the level of classical mechanics. I consider two related symmetries, time reversal invariance and what I call ‘Wigner reversal invariance.’ Violation of (...) the first is interesting, for not only would it fly in the face of the usual story about temporal symmetry, but it also appears to imply (as I’ll explain) that time is ‘handed’, or as some have misleadingly said in the literature, ‘anisotropic’. Violation of the second is, as I hope to show, even more interesting. The paper also contains a discussion of two mostly neglected topics: what it means to say time is handed and what warrants such an attribution to time. (shrink)

Kant's argument from incongruent counterparts for substantival space is examined; it is concluded that the argument has no force against a relationist. The argument does suggest that a relationist cannot give an account of enantiomorphism, incongruent counterparts and orientability. The prospects for a relationist account of these notions are assessed, and it is found that they are good provided the relationist is some kind of modal relationist. An illustration and interpretation of these modal commitments is given.

This paper considers the implications for the relational-substantival debate of observations of parity nonconservation in weak interactions, a much neglected topic. It is argued that 'geometric proofs' of absolute space, first proposed by Kant (1768), fail, but that parity violating laws allow 'mechanical proofs', like Newton's laws. Parity violating laws are explained and arguments analogous to those of Newton's Scholium are constructed to show that they require absolute spacetime structure--namely, an orientation--as Newtonian mechanics requires affine structure. Finally, it is considered (...) how standard relationist responses to Newton's argument might respond to the new challenge of parity nonconservation. (shrink)

The positivistic Received View construed scientific theories syntactically as axiomatic calculi where theoretical terms were given a partial semantic interpretation via correspondence rules connecting them to observation statements. This paper assesses what, with hindsight, seem the most important defects in the Received View; surveys the main proposed successor analyses to the Received View—various Semantic Conception versions and the Structuralist Analysis; evaluates how well they avoid those defects; examines what new problems they face and where the most promising require further development (...) or leave unanswered questions; explores implications of recent work on models for understanding theories; and rebuts the few criticisms of the Semantic Conception that have surfaced. (shrink)

INTRODUCTION TO THE ARGUMENT OF 1768 Some ordinary facts about the world we live in can be readily explained by other ordinary facts. One can, for example, explain the fact that when we are facing north the sun rises on the right and ...

The purpose of this paper is twofold. First, I want to examine some rather curious arguments of Kant’s which purport to show that some alleged properties of space can be derived from some alleged facts about incongruous counterparts. Secondly, I want to give some preliminary answers to some important questions about the distinction between right and left and the nature of space and space-time which are raised by Kant’s argument. As a byproduct, I hope that the discussion will provide an (...) example of how science can illuminate philosophical issues and of how philosophy can at least lead one into interesting scientific issues. (shrink)

In his 1768 essay ‘Concerning the Ultimate Foundation of the Differentiation of the Regions in Space’, Kant used incongruent counterparts in an attempt to refute a Leibnizian-relationist account of space. It is hard to imagine that scholars could be more divided on how to understand Kant’s argument and on how to assess its effectiveness. Two years later in 1770 incongruent counterparts resurface in Kant’s Inaugural Dissertation, this time as part of a proof that our knowledge of space is intuitive. They (...) appear yet again in the Prolegomena and the Metaphysical Foundations of Natural Science as part of the argument for transcendental idealism. Not surprisingly, scholars are also at odds on how to explain the shifts in the roles Kant wanted incongruent counterparts to play and how to assess the importance of these matters for the development of his critical philosophy. (shrink)