Explanation

Philosophical reflections about explanation are common in the history of philosophy, and important proposals were made by Aristotle, Hume, Kant and Mill. But the subject came of age in the twentieth century with the provision of detailed models of scientific explanation, prominently the covering-law model, which takes explanations to be arguments in which a law of nature plays an essential role among the premises. In the heyday of logical empiricism, philosophers achieved a consensus on the covering law model, but, during the 1960s and 1970s, that consensus was challenged through the recognition of four major kinds of difficulty: first, a problem about the relation between idealized arguments and the actual practice of explaining; second, the difficulty of characterizing the underlying notion of a law of nature; third, troubles in accounting for the asymmetries of explanation; and, four, recalcitrant problems in treating statistical explanations. Appreciation of these difficulties has led to the widespread abandonment of the covering-law model, and currently there is no consensus on how to understand explanation. The main contemporary view seeks to characterize explanation in terms of causation, that is, explanations are accounts that trace the causes of the events (states, conditions) explained. Other philosophers believe that there is no general account of explanation, and offer pragmatic theories. A third option sees explanation as consisting in the unification of the phenomena. All of these approaches have associated successes, and face particular anomalies. Although the general character of explanation is now a subject for philosophical debate, some particular kinds of explanation seem to be relatively well understood. In particular, functional explanations in biology, which logical empiricists found puzzling, now appear to be treated quite naturally by supposing them to make tacit reference to natural selection.