Abstract
Jack Spencer argues we should reject a decision rule called MaxRat because it's incompatible with this principle: If you know that you will choose an option, x, and you know that x is better than every other option available to you, then it is permissible for you to choose x. I agree with Spencer that defenders of MaxRat should reject this principle. However, I disagree insofar as he suggests that he and orthodox causalists are in a position to accept it. Both orthodox CDT and Spencer's own theory of rational choice are incompatible with the principle as well. It is surprising to realise, but all are agreed: it can be irrational to knowingly choose the best.