 One broad line of response to the problem of counterfactual isomorphs has been to distinguish between ‘default’ (or ‘normal’) and ‘deviant’ events, and to build this distinction into the way in which causal information is extracted from the model. For example, Menzies’ approach exploits the machinery seen above with respect to Hithcock’s solution to the problem of symmetric overdetermination, which involves fixing ‘off-path’ variables at non-actual values. Menzies’ suggestion is that we fix those variables at their ‘most normal’ values, so that in effect we evaluate the relevant counterfactuals from the perspective of a world where those normal values are actualised rather than from the perspective of the actual world (Menzies 2004, 2007, 2009).