Barry Loewer

My primary focus in this paper is on an objection to Humean account of laws and specifically to David Lewis’ “best systems analysis” (BSA). The objection is that the laws according to the BSA (which I call L-laws) fail to account for the ability of laws to explain. In contrast governing laws (which I will call G-laws) are alleged to account for the role of laws in scientific explanations by virtue of their governing role. If governing is required for laws to be explanatory then Humean accounts like Lewis’ are dead in the water since explanation is central to the role of laws in the sciences. However, I will argue that there are effective rebuttals to arguments that Humean laws don’t explain and that actually it is governing accounts that have difficulty with explanation.

This paper develops an account of the metaphysics of fundamental laws I call “the Package Deal Account ” that is a descendent of Lewis’ BSA but differs from it in a number of significant ways. It also rejects some elements of the metaphysics in which Lewis develops his BSA. First, Lewis proposed a metaphysical thesis about fundamental properties he calls “Humean Supervenience” according to which all fundamental properties are instantiated by points or point sized individuals and the only fundamental relations are geometrical spatial and temporal relations between these. While the BSA does not require HS Lewis seems to hope that it is true. In contrast, the PDA is not committed to HS or even to the fundamental arena in which fundamental properties are instantiated possessing geometrical structure and thus is able to accommodate relations and structures found in contemporary physics that apparently conflict with HS. Second, although Lewis’ BSA doesn’t require HS his Humeanism does require that fundamental properties are categorical. In contrast, the PDA allows for the possibility that fundamental properties are individuated in terms of laws and so are not categorical. Third, the PDA expands and develops the criteria for what counts in favor of a candidate system with more attention to the criteria employed by physicists in evaluating proposed theories. Fourth and most importantly, unlike Lewis’ BSA, the PDA does not presuppose metaphysically primitive elite properties/quantities that Lewis calls “perfectly natural” properties/quantities or presuppose a metaphysically preferred language whose terms denote such properties/quantities. It replaces Lewis’ account with an account on which natural properties are not metaphysically prior to the laws but are elements of a package that includes a fundamental arena that plays the role of space-time as well as fundamental laws and properties. By doing so it responds to some epistemological and metaphysical issues that have been raised regarding natural properties and their role in the BSA. In sum, the PDA goes further in explicating the notion of laws in terms of the aims and practices of science especially fundamental physics rather than in terms of prior metaphysics. I begin by reviewing Lewis’ account of perfectly natural properties and his Humean BSA of laws.

In _A Companion to David Lewis_, Barry Loewer and Jonathan Schaffer bring together top philosophers to explain, discuss, and critically extend Lewis's seminal work in original ways. Students and scholars will discover the underlying themes and complex interconnections woven through the diverse range of his work in metaphysics, philosophy of language, logic, epistemology, philosophy of science, philosophy of mind, ethics, and aesthetics. The first and only comprehensive study of the work of David Lewis, one of the most systematic and influential philosophers of the latter half of the 20th century Contributions shed light on the underlying themes and complex interconnections woven through Lewis's work across his enormous range of influence, including metaphysics, language, logic, epistemology, science, mind, ethics, and aesthetics Outstanding Lewis scholars and leading philosophers working in the fields Lewis influenced explain, discuss, and critically extend Lewis's work in original ways An essential resource for students and researchers across analytic philosophy that covers the major themes of Lewis's work

NRP is a family of views differing by how they understand “reduction” and “physicalism.” Following Kim I understand the non-reduction as holding that some events and properties are distinct from any physical events and properties. A necessary condition for physicalism is that mental properties, events, and laws supervene on physical ones. Kim allows various understandings of “supervenience” but I think that physicalism requires at least the claim that any minimal physical duplicate of the actual world is a duplicate simpliciter. Some complications aside this means that true mental propositions, e.g. Jaegwon is thinking about sailing, are metaphysically entailed by true physical propositions. Kim says that supervenience is too weak to capture the root idea of physicalism that mental property instantiations depend on physical property instantiations so he adds that the mental depends on the physical. One way in which this dependance might be spelled out is that mental properties are higher order functional properties whose instantiations are realized by instantiations of physical properties. An event is an instantiation of a property by an individual and a time. A mental event is the instantiation of a mental property. Not every predicate expresses a genuine property. Kim further suggests that properties are individuated, at least partly, by nomological and causal relations. For physicalism to have content something must be said about the difficult issue of characterizing the physical. Kim’s view seems to be that the micro-physical properties of ideal physics are physical. He also counts as physical properties that are conjunctions and aggregates of micro-physical properties and higher level properties defined over lower-level physical properties.. Since these latter two classes of properties supervene on the micro-properties and laws there is no need to include them in the supervenience base.

The appeal of materialism lies precisely in this, in its claim to be natural metaphysics within the bounds of science. That a doctrine which promises to gratify our ambition (to know the noumenal) and our caution (not to be unscientific) should have great appeal is hardly something to be wondered at. (Putnam (1983), p.210) Materialism says that all facts, in particular all mental facts, obtain in virtue of the spatio- temporal distribution, and properties, of matter. It was, as Putnam says, “metaphysics within the bounds of science”, but only so long as science was thought to say that the world is made out of matter.1 In this century physicists have learned that there is more in the world than matter and, in any case, matter isn’t quite what it seemed to be. For this reason many philosophers who think that metaphysics should be informed by science advocate physicalism in place of materialism. Physicalism claims that all facts obtain in virtue of the distribution of the fundamental entities and properties –whatever they turn out to be- of completed fundamental physics. Later I will discuss a more precise formulation. But not all contemporary philosophers embrace physicalism. Some- and though a minority not a small or un-influential one- think that physicalism is rather the metaphysics for an unjustified scientism; i.e. it is scientistic metaphysics. Those among them that think that physicalism can be clearly formulated think that it characterizes a

It is generally thought that objective chances for particular events different from 1 and 0 and determinism are incompatible. However, there are important scientific theories whose laws are deterministic but which also assign non-trivial probabilities to events. The most important of these is statistical mechanics whose probabilities are essential to the explanations of thermodynamic phenomena. These probabilities are often construed as 'ignorance' probabilities representing our lack of knowledge concerning the microstate. I argue that this construal is incompatible with the role of probability in explanation and laws. This is the 'paradox of deterministic probabilities'. After surveying the usual list of accounts of objective chance and finding them inadequate I argue that an account of chance sketched by David Lewis can be modified to solve the paradox of deterministic probabilities and provide an adequate account of the probabilities in deterministic theories like statistical mechanics

Among the most important questions in the metaphysics of science are "What are the natures of fundamental laws and chances?" and "What grounds the direction of time?" My aim in this paper is to examine some connections between these questions, discuss two approaches to answering them and argue in favor of one. Along the way I will raise and comment on a number of issues concerning the relationship between physics and metaphysics and consequences for the subject matter and methodology of metaphysics