 The nature of the strict laws required by the cause-law principle is as follows. For any causal relationship between particular events e1 and e2, there must be a law of the form ‘(C1 &amp; D1) → D2’, where ‘C1’ states a set of standing conditions, and ‘D1’ is a description of e1 that is sufficient, given C1, for the occurrence of an event of the kind ‘D2’, which is a description of e2. Traditionally, a strict law has been thought of as one where the condition and event-types specified in the antecedent are such as to guarantee that the condition or event-types specified in the consequent occur—the latter must occur if the former in fact obtain. But indeterministic or probabilistic versions of strict laws are possible as well (Davidson 1970, 219). The point that distinguishes strict laws is not so much the guaranteeing of the effect by satisfaction of the antecedent as the inclusion, in the antecedent, of all conditions and events that can be stated that could possibly prevent the occurrence of the effect. A strict indeterministic law would be one that specified everything required in order for some effect to occur. If the effect does not occur when those conditions obtain, there is nothing else that could be cited in explanation of this failure (other than the brute fact of an indeterministic universe). For reasons of simplicity, we will assume determinism in this discussion, though what is said about strict laws could be carried over without remainder to strict indeterministic laws.