 Deterministic SEMs naturally give rise to a logic of counterfactuals. These counterfactuals are called structural counterfactuals or interventionist counterfactuals. Structural counterfactuals are similar in some ways to what Lewis (1979) calls non-backtracking counterfactuals. In a non-backtracking counterfactual, one does not reason backwards from a counterfactual supposition to draw conclusions about the causes of the hypothetical situation. For instance, one would not reason “If the meat had been cooked rare, then the flame would have been set to low”. Lewis (1979) proposes that we think of the antecedent of a counterfactual as coming about through a minor “miracle”. The formalism for representing interventions described in the previous section prevents backtracking from effects to causes.