 It was useful in taxonomizing the seven variations of the counterfactual test to show how such variations were produced in response to problems perceived to exist for the first variation, which was the simple, unmodified counterfactual test. While there is no test of proximate causation that is comparably dominant in law (even if only in lip service) to the counterfactual test of cause-in-fact, it is nonetheless useful to display the various proximate cause tests as they react to problems in other tests of proximate causation. Some discussion of standard problems with each version of the tests within legal theory is thus included as we describe what motivates others of the tests. 