Online research in philosophy

Laws form counterfactually stable sets -- Natural necessity -- Three payoffs of my account -- A world of subjunctives.

After reviewing several failed arguments that laws cannot change, I use the laws' special relation to counterfactuals to show how temporary laws would have to differ from eternal but time-dependent laws. Then I argue that temporary laws are impossible and that neither Lewis's nor Armstrong's analyses of law nicely accounts for the laws' immutability. *Received September 2006; revised September 2007. ‡Many thanks to John Roberts and John Carroll for valuable comments on earlier drafts, as well as to several anonymous referees for their good suggestions. †To contact the author, please write to: Department of Philosophy, University of North Carolina, CB #3125, Caldwell Hall, Chapel Hill, NC 27599-3125; e-mail: mlange@email.unc.edu.

A law about frequencies would be a law of nature that imposes a constraint on one or more (actual, global) frequencies. On any of the leading philosophical approaches to laws of nature, there could be laws about frequencies. Hypotheses that posit laws about frequencies turn out to behave very similarly to hypotheses that posit corresponding laws about probabilities or chances -- they make the same predictions, provide similar explanations, and are confirmed or disconfirmed by empirical evidence in the same ways. This makes it interesting to consider the possibility of interpreting probabilistic laws from scientific theories as laws about frequencies. This is surprising proposal, but I argue that the resulting view (which I call 'nomic frequentism') is able to overcome all of the standard objections to frequentist interpretation of objective probabilities.

It is a commonplace that one of the primary tasks of natural science is to discover the laws of nature. Those who don’t think that nature has laws will of course disagree; but of those who do, most will be in accord with Armstrong when he writes that natural science, having discovered the kinds and properties of things, should “state the laws” which those things “obey” (Armstrong What is a law 3). No Scholastic philosopher would have included the discovery of the laws of nature among the aims of natural philosophy. Regularities there may be in an Aristotelian world, but the focus of inquiry is elsewhere —on natural kinds, powers, qualities, temperaments. There must have been a change of view at some point. The obvious period in which to look for that change is that period in which the notion of law came to the fore in natural philosophy: the seventeenth century. Though there has been occasional dissension, that notion has been with us ever since. Scientists are quite happy to talk about all sorts of laws, from the basic laws of conservation to “phenomenological” and statistical laws. Philosophers, on the other hand, have found them puzzling. The character attributed to laws seems to be in need of explanation, and yet no convincing explanation is at hand; indeed, as I have mentioned, some philosophers think that natural science has no laws, or at least that it doesn’t need to appeal to them to accomplish its ends. My suggestion will be that the configuration of features characteristic..

Recently several thought experiments have been developed (by John Carroll amongst others) which have been alleged to refute the Ramsey-Lewis view of laws of nature. The paper aims to show that two such thought experiments fail to establish that the Ramsey-Lewis view is false, since they presuppose a conception of laws of nature that is radically at odds with the Humean conception of laws embodied by the Ramsey-Lewis view. In particular, the thought experiments presuppose that laws of nature govern the behavior of objects. The paper argues that the claim that laws govern should not be regarded as a conceptual truth, and shows how the governing conception of laws manifests itself in the thought experiments. Hence the thought experiments do not constitute genuine counter-examples to the Ramsey-Lewis view, since the Humean is free to reject the conception of laws which the thought experiments presuppose.

Humean accounts of law are at the same time accounts of causation. Accordingly, since laws are nothing but contingent cosmic regularities, to be a cause is just to be an instance of such a law. Every particular cause-effect pair, according to these accounts, instantiates some law of nature. I argue that this claim is false. Singular causation without being governed by any law is logically and physically possible. Separating causes from laws enables us to see the distinct role each plays in science, especially in matters related to prediction and explanation.

Metaphysicians speak of laws of nature in terms of necessity and universality; scientists, in terms of symmetry and invariance. In this book van Fraassen argues that no metaphysical account of laws can succeed. He analyzes and rejects the arguments that there are laws of nature, or that we must believe there are, and argues that we should disregard the idea of law as an adequate clue to science. After exploring what this means for general epistemology, the author develops the empiricist view of science as a construction of models to represent the phenomena.

Some scientists try to discover and report laws of nature. And, they do so with success. There are many principles that were for a long time thought to be laws that turned out to be useful approximations, like Newton’s gravitational principle. There are others that were thought to be laws and still are considered laws, like Einstein’s principle that no signals travel faster than light. Laws of nature are not just important to scientists. They are also of great interest to us philosophers, though primarily in an ancillary way. Qua philosophers, we do not try to discover what the laws are. We care about what it is to be a law, about lawhood, the essential difference between something’s being a law and something’s not being a law. It is one of our jobs to understand lawhood and convey our understanding to others.

This book outlines a major new theory of natural laws. The book begins with the question of whether there are any genuinely law-like phenomena in nature. The discussion addresses questions currently being debated by metaphysicians such as whether the laws of nature are necessary or contingent and whether a property can be identified independently of its causal role.