 Adopting a more heavyweight account of the nature of metaphysical laws, and hence of metaphysical explanation, may come with a metaphysical cost—for instance, if one takes them to be ontologically basic entities, or if one takes the distinction between laws and non-laws to be a primitive one. According to proponents of such an account, this is a price worth paying. One important reason why the traditional deductive-nomological account of (scientific) explanation has few proponents today was that the symmetry of deductive entailment in certain cases seemed to interfere with our intuitions about the asymmetry of explanation (e.g., Lehrer 1974, who gets the example from Bromberger’s (1966) famous flagpole/shadow example, see also the entry  scientific explanation §2.5).  If the laws that explanation invokes involve or even reduce to something which has direction (from more to less fundamental) already built in, this problem is entirely avoided. Of course, if the account is to be able to also cover metaphysical explanation in the sense of essentialist explanation (see  §2  above), the fact that the laws have direction already built in could be considered a flaw rather than an advantage.