In the previous chapter an account of uninstantiated laws was given. According to this view, strictly there are no uninstantiated laws. Statements of uninstantiated law tell us that a certain law would govern the antecedent universal, if, contrary to fact, that universal existed, that is, was somewhere instantiated. Such an account deals fairly easily with the problem of ‘missing values’ of functional laws. But certain cases of uninstantiated laws have been suggested by Michael Tooley (1977) which the counterfactual account appears to be unable to handle.

Tooley's cases

The cases to be discussed are not actual uninstantiated laws proposed by scientists. They are imaginary situations where, it is plausible to say, we should be inclined to postulate uninstantiated laws. Tooley himself was not concerned with the topic of uninstantiated laws for its own sake. Rather he wanted to use the cases, first to criticize the Regularity theory, and second to support the view that laws of nature are relations between universals. I largely followed him in his estimation of the cases in my 1978 (Ch. 24). Now I have doubts.

The Fundamental Particle case (1977, p. 669). Tooley imagines a world containing ten, and only ten, types of fundamental particle. Allowing that a particle may interact with a particle of its own type as well as with particles of other types, this allows for 55 interaction laws governing the interaction of pairs of particles. Suppose that 54 of these laws are known. They prove in each case to be so idiosyncratic that, given any 53 of them, the nature of the 54th could not be known, or even rationally conjectured, antecedently to experience. But suppose that the 55th law, the law of the interaction of B-type with J-type particles, is not known. This occurs because, although this type of interaction is physically possible, yet boundary conditions in the universe are such that, throughout all time, no B-particle is ever close enough to a J-particle to interact with it.

Tooley claims that, in this situation, we would have good reason to assert the existence of an uninstantiated law governing B–J interactions.