 Very generally, there are four sorts of problems with the counterfactual test for causation in fact that are raised in the legal literature. The first of these problems has to do with proof and evidence. As an element of the prima facie case, causation in fact must be proven by the party with the burden of proof. In criminal cases, that is the prosecution, who must prove beyond a reasonable doubt what would have happened absent the defendant’s act. Counterfactuals by their nature are difficult to prove with any degree of certainty, for they require the fact finder to speculate what would have happened if the defendant had not done what she in actual fact did. Suppose a defendant culpably destroys a life preserver on a seagoing tug. When a crewman falls overboard and drowns, was a necessary condition of his death the act of the defendant in destroying the life preserver? (New York Central RR. v. Grimstad). If the life preserver had been there, would anyone have thought to use it? thrown it in time? thrown it far enough? gotten it near enough to the victim that he would have reached it? We often lack the kind of precise information that could verify whether the culpable act of the defendant made any difference in this way.