The purpose of this essay is to defend the deductive-nomological model
of explanation against a number of criticisms that have been made of it.
It has traditionally been thought that scientific explanations were
causal and that scientific explanations involved deduction from laws. In
recent years, however, this three-fold identity has been challenged:
there are, it is argued, causal explanations that are not scientific,
scientific explanations that are not deductive, deductions from laws
that are neither causal explanations nor scientific explanations, and
causal explanations that involve no deductions from laws. The aim of the
present essay is to defend the traditional identities, and to show that
the more recent attempts at invalidating them fail in their object. More
specifically, this essay argues that a Humean version of the
deductive-nomological model of explanation can be defended as (1) the
correct account of scientific explanation of individual facts and
processes, and as (2) the correct account of causal explanations of
individual facts and processes. The deductive-nomological model holds
that to explain an event E, say that a is G, one must find some initial
conditions C, say that a is F, and a law or theory T such that T and C
jointly entail E, and both are essential to the deduction.