Carving Nature at Its Joints: Natural Kinds in Metaphysics and Science

4. Lange and Laws, Kinds, and Counterfactuals

4 In this essay I examine and question Marc Lange’s account of laws, and his claim in the preceding chapter that the law delineating the range of natural kinds of fundamental particle has a lesser grade of necessity than do laws connecting the fundamental properties of those kinds with their derived properties. 1 Lange on Laws Regularity theorists about laws face the following problem: many regularities are true, but only some of them correspond to laws. Consider: (S1) All bits of copper conduct electricity; (S2) All lumps of gold have a volume of less than a cubic mile. These two generalizations are both true. However, of (N1) It is a law that all bits of copper conduct electricity; (N2) It is a law that all lumps of gold have a volume of less than a cubic mile, only the first is true. The trick for the regularity theorist is to pick from among the regularities those that are like (S1), for which the addition of the nomic operator ‘it is a law that . . . ’ is truth-preserving, while excluding those like (S2), for which that operator yields a falsehood. Marc Lange is no regularity theorist, but his starting question is very similar to that posed for the regularity theorist. Consider all the true propositions that are not facts about which laws there are—propositions that can be expressed without using vocabulary such as ‘law’, ‘nomological’ and the like. Call this set ‘Σ’. Propositions such as (S1) and (S2) are in Σ because they are true and don’t concerns laws. (N1) is excluded because although true, it concerns a law; (N2) is doubly excluded because it concerns an alleged law and is false. Σ is the set of what Lange call the “sub-nomic” Lange and Laws, Kinds, and Counterfactuals Alexander Bird 86 A. Bird facts. They are sub-nomic because they don’t concern which laws there are; they are not expressed using nomic vocabulary. Some of the facts in Σ are those like (S1) for which the nomic operator is truth-preserving. These are, of course, the laws.1 I will use ‘accident’ as the term for the remaining members of Σ that are like (S2), for which the nomic operator takes us from a truth to a falsehood. How do we separate the laws in Σ from the accidents? Lange’s approach is to exploit their superior stability under counterfactual suppositions. Consider: (G1) Were Bill Gates to want some non-conducting copper, all bits of copper would still conduct electricity; (G2) Were Bill Gates to want a lump of gold with a volume greater than a cubic mile, all lumps of gold would still have a volume of less than a cubic mile. These are counterfactual (or better, subjunctive) conditionals of a mildly unusual sort, where although the antecedent is counter-to-fact (i.e., false), their consequents are true. But they do not require any special kind of treatment. We can see that while (G1) is certainly true, (G2) is quite possibly false. Powerful though Bill Gates is, there are some accidents that would remain true, whatever he wanted. Using the Gates antecedent allows us to divide Σ into two sets: one includes the laws and other things that Gates is not powerful enough to change, the other set includes the things Gates could possibly change. We may be able to generalize the strategy that distinguishes between (G1) and (G2) by considering more powerful counterfactual antecedents in conditionals such as (G1) and (G2). On the other hand, we don’t want the counterfactual supposition to be too powerful: The transition elements are all non-conductors ⵧ→ all bits of copper conduct electricity looks to be false. Think of our conditionals as having the following form: (T) C ⵧ→ F where ‘C’ denotes a counterfactual supposition and ‘F’ denotes an actual fact. The generalized Gates test suggests that (T) will always be true when F is a legal truth and C is an accident, but will sometimes be false when both are nomological facts or both are accidents. Lange’s account of lawhood proposes that the laws are those that are stable under any counterfactual supposition that is an accident (or its negation).2 As an account Lange and Laws, Kinds, and Counterfactuals 87 of law, that looks to be problematic because it employs a concept ‘accident’ that is itself a concept of the kind we are wishing to elucidate: accidents are precisely the...