The basic kinds of physical causality that are foundational for other kinds of causality involve objects and the causal relations between them. These interactions do not involve events. If events were ontologically significant entities for causality in general, then they would play a role in simple mechanical interactions. But arguments about simple collisions looked at from different frames of reference show that events cannot play a role in simple mechanical interactions, and neither can the entirely hypothetical causal relations between events. (...) These arguments show that physics, which should be authoritative when it comes to the metaphysics of causality, gives no reasons to believe that events are causal agents. Force relations and some cases of energy-momentum transfer are examples of causal relations, with forces being paradigmatic in the macroscopic world, though it is conceivable that there are other kinds of causal relation. A relation between two objects is a causal relation if and only if when it is instantiated by the two objects there is a possibility that the objects that are the terms of the relation could change. The basic metaphysics of causality is about objects, causal relations, changes in objects, and a causal primitive. The paper also includes a discussion of the metaphysics of forces and a discussion of the metaphysics of energy and momentum exchanges. (shrink)

The Great Divide in metaphysical debates about laws of nature is between Humeans, who think that laws merely describe the distribution of matter, and non-Humeans, who think that laws govern it. The metaphysics can place demands on the proper formulations of physical theories. It is sometimes assumed that the governing view requires a fundamental / intrinsic direction of time: to govern, laws must be dynamical, producing later states of the world from earlier ones, in accord with the fundamental direction of (...) time in the universe. In this paper, we propose a minimal primitivism about laws of nature (MinP) according to which there is no such requirement. On our view, laws govern by constraining the physical possibilities. Our view captures the essence of the governing view without taking on extraneous commitments about the direction of time or dynamic production. Moreover, as a version of primitivism, our view requires no reduction / analysis of laws in terms of universals, powers, or dispositions. Our view accommodates several potential candidates for fundamental laws, including the principle of least action, the Past Hypothesis, the Einstein equation of general relativity, and even controversial examples found in the Wheeler-Feynman theory of electrodynamics and retrocausal theories of quantum mechanics. By understanding governing as constraining, non-Humeans who accept MinP have the same freedom to contemplate a wide variety of candidate fundamental laws as Humeans do. (shrink)

I will argue, pace a great many of my contemporaries, that there's something right about Boltzmann's attempt to ground the second law of thermodynamics in a suitably amended deterministic time-reversal invariant classical dynamics, and that in order to appreciate what's right about (what was at least at one time) Boltzmann's explanatory project, one has to fully apprehend the nature of microphysical causal structure, time-reversal invariance, and the relationship between Boltzmann entropy and the work of Rudolf Clausius.