 The logic of structural counterfactuals has been developed by Galles and Pearl (1998), Halpern (2000), Briggs (2012), and Zhang (2013a). This section will focus on Briggs’ formulation; it has the richest language, but unlike the other approaches it can not be applied to causal models with cycles. Despite a shared concern with non-backtracking counterfactuals, Briggs’ logic differs in a number of ways from the more familiar logic of counterfactuals developed by Stalnaker (1968) and Lewis (1973b).