The role of cause and effect in Hume's theory of ideas

A philosopher's reliance on examples confronts the interpreter with the problem of determining what, and how much, of the object or situation portrayed is pertinent to his purpose, and what is extraneous, even vital to ignore. The point of an example can be distorted, obliterated, or even turned on its head if the focus is misplaced. A case in point is Hume's favorite example of causation, the collision of two billiard-balls. While a graphic illustration of the impossibility of direct insight, unaided by experience, into causal connections, it is apt to lead one to believe that the proper vantage from which to regard Hume's account of causal relations is the physical world. In my view, nothing could be further from the truth. The most significant and distinctive function of causal relations in Hume's theory of understanding is discharged well before a world of minds and bodies is even possible. Failure to bracket out the physical character of billiard-balls or the mental content of sensations, reflexions, and thoughts is therefore likely to be the occasion of considerable misunderstanding.

Few, if any, interpreters of Hume share this view. They regard him as the philosopher of natural – that is, naïve – human understanding, access to which is simply a matter of letting come to mind what most readily does.