The determination of the true measure of damage in any individual case is seldom easy. It depends upon considerations of causation, and causation is primarily a matter for philosophic rather than legal inquiry. Hume was not prepared to adopt the ordinary conception of causation. ‘It were infinite for the law to judge the causes of causes and their impulsion one of another,’ said Bacon. In a modern case the same thought has been expressed in the words ‘Causation is not a chain but a net.’ Faced with metaphysical uncertainty the lawyer must find some base on which to build his structure, and he does it by following the course of the pragmatist and asking of any particular decision: Does it work ? If it does he has to fit it into a scheme which should be consistent with a number of other decisions which also work, but are not always governed by the strict rules of logic.