Callum Duguid

Paradigmatic examples of laws drawn from physics are accompanied by a rich explanatory structure that supports unificatory efforts. Part of the reason these efforts have been successful has been their identification of conservation laws, whose greater necessity allows them to act as constraints. Within biology, much of the debate over lawhood has focused on whether restricted regularities should be treated as laws, rather than finding parallels to how physical laws are structured. This paper argues that extending that structure to biology is both possible and well-motivated by building on the functionalist approach to lawhood. Through two specific examples – the West Brown Enquist model of metabolism and the neutral theory of biodiversity – I show there are principles in biological theorising that can be interpreted as analogues of conservation laws. This reveals a similarity of nomological structure between physics and biology which is often obscured by methodological differences. Commitment to these laws in biology supports the view that theoretical progress can be made by focusing research efforts on unificatory principles.

Symmetry principles are a central part of contemporary physics, yet there has been surprisingly little metaphysical work done on them. This article develops the Wignerian treatment of symmetries as higher-order laws—metalaws—within a Humean framework of lawhood. Lange has raised two obstacles to Humean metalaws, and the article shows that the account has the resources available to respond to both. It is argued that this framework for Humean metalaws stands as an example of naturalistic metaphysics, able to bring Humeanism into contact with the practice of actual science without giving up on the central denial of necessary connections.

A long-standing charge of circularity against regularity accounts of laws has recently seen a surge of renewed interest. The difficulty is that we appeal to laws to explain their worldly instances, but if these laws are descriptions of regularities in the instances then they are explained by those very instances. By the transitivity of explanation, we reach an absurd conclusion: instances of the laws explain themselves. While drawing a distinction between metaphysical and scientific explanations merely modifies the challenge rather than resolving it, I argue that it does point us towards an attractive solution. According to Humeanism, the most prominent form of the regularity view, laws capture information about important patterns in the phenomena. By invoking laws in scientific explanations, Humeans are showing how a given explanandum is subsumed into a more general pattern. Doing so both undermines a principle of transitivity that plays a crucial role in the circularity argument and draws out a central feature of the Humean approach to scientific explanation.