Model of explanation according to which to explain an event by reference to another event necessarily presupposes an appeal to laws or general propositions correlating events of the type to be explained (explananda) with events of the type cited as its causes or conditions (explanantia).
It is rooted in David Hume 's doctrine that, when two events are said to be causally related, all that is meant is that they instantiate certain regularities of succession that have been repeatedly observed to hold between such events in the past. This doctrine was given more rigorous expression by the logical positivist Carl Hempel (1905–1997).