In his new book "The Importance of Being Rational", Errol Lord aims to give a real definition of the property of rationality in terms of normative reasons. If he can do so, his work is an important step towards a defense of ‘reasons fundamentalism’ – the thesis that all complex normative properties can be analyzed in terms of normative reasons. I focus on his analysis of epistemic rationality, which says that your doxastic attitudes are rational just in case they are correct responses to the objective normative reasons you possess. For some fact to be an objective normative reason to do something that you possess, you have to be in a position to know this fact and be able to competently use it as a reason to do that thing. Lord’s view is th...