Equally Effective Causes
Penelope Mackie (2000, this issue) accuses my (1995) theory of causation of committing me to 'making distinctions between facts which, in combination with [my] account of the extent to which a cause raises the chance of its effect, produces anomalous results'. I deny the charge. In Mackie's example, of a climber Don dying by falling head down off a cliff, she distinguishes two factual causes of the fact that Don dies: F, the fact that Don falls, and F*, the fact that he falls head down. In the case that she thinks gives me trouble, the relevant chances of Don's dying are 1 if he falls head down (F"), 0.2 if he falls but not head down (F & -F*), and 0 if he does not fall (-F). Then if the other conditions I impose on causation are met, it follows on my theory, which requires causes to raise the chances of their effects, that Don dies both because he falls and because he falls head down.