 A similar problem arises for attempts to explain normativity in terms of the idea of a categorical requirement of rationality. There is a standardly accepted distinction between hypothetical requirements and categorical ones (Kant 1785 [1981]). Hypothetical requirements are, roughly, requirements that are grounded in, or hold in virtue of, the contingent desires or attitudes of the agent who is so required. An example might be the requirement to maintain your car, which presumably presupposes that you want your car to continue running. Categorical requirements have no such presupposition. It might seem that any genuinely robust normative requirement would be categorical, since all other requirements depend on, and so are hostage to, facts about person’s contingent psychology.