 Condition (i) brings to mind the earlier discussion of robustness  (§4.2.2),  but (iii) is the focus at the moment, as it shows why Kurt’s sit-and-whistle alternative is not enough to ground his responsibility: it was not reasonable for him to consider this as an option. McKenna rejects PAP as “too inclusive”, favoring instead a principle with these more significant constraints. Having said that, he argues that even this improved principle falls to an FSC, one that, however, leaves open plenty of insignificant alternatives to assuage libertarian concerns (see Robinson 2014 for critical discussion).