 According to  Naive Dominance,  it is irrational to practise. After all, whether or not I pass or fail, I obtain higher utility if I don’t practise, so not practising strongly dominates practising. But this is clearly the wrong result. The reason is that I should not compare practising at the world at which I pass with not practising at that world, and practising at the world at which I fail with not practising at that world. For if I practise, I will pass; and if I don’t, I will fail. Moreover, I know all this. So I should compare practising at the world at which I pass with not practising at the world at which I fail. And then my utility is higher if I practise.