Laws and Reasons Why

Laws play some role in explanations: at the very least, they somehow connect what is explained, or the explanandum , to what explains, or the explanans . Thus, thermodynamical laws connect the match's being struck and its lightning, so that the former causes the latter; and laws about set formation connect Socrates' existence with {Socrates}'s existence, so that the former grounds the latter. But is there more to the explanatory role of laws? A natural proposal, which finds considerable support in the literature, is that laws simply are reasons why. That is, besides connecting the explanandum with a suitable ground or cause, they take part, together with these, in explaining why the explanandum obtains. In this paper, I present two arguments that show that this proposal cannot hold in general. They each point to one unacceptable consequence: a suspicious infinite extendibility of explanantia; and a failure of the irreflexivity of “because.”