ABSTRACT
Few commentators have believed that David Hume succeeds in giving an 'exact definition' of causation. The main objections to his account are well-known. Commentators have responded in different ways to the challenge of making sense of these two definitions within a unified theory. Some have argued that only the first of the two definitions represents Hume's real view of causation. Hume presents his lengthy discussion of probable argument as a detour justified by the light it might shed on the nature of the troublesome but essentially important idea of necessity. Causal beliefs are acquired by custom, as a result of regularities in our experience. Constant conjunction produces an association of ideas, causing the mind to pass from the impression of a cause to 'the conception and belief of the usual effect'. Hume is in a position to 'collect all the different parts of this reasoning, and by joining them together form an exact definition of the relation of cause and effect'.
