“Mattering as a means is a way of mattering. Your desires would be pointless only if acting rationally did not matter. S claims that, when you are deciding what to do, compared with acting rationally, nothing matters more. This claim is justified even when what it would be rational for you to do is to make yourself disposed to act irrationally. What matters most, even here, is that you do what it would be rational for you to do.”

— Derek Parfit, Reasons and Persons (1984), p. 46