to satisfy our desires: 'go to the doctor' is a hypothetical imperative because we are only obliged to obey it if we want to get well. A categorical imperative binds us regardless of our desires: everyone has a duty to not lie, regardless of circumstances and even if it is in our interest to do so. These imperatives are morally binding because they are based on reason, rather than contingent facts about an agent. Unlike hypothetical imperatives, which bind us insofar as we are part of a group or society which we owe duties to, we cannot opt out of the categorical imperative because we cannot opt out of being rational agents. We owe a duty to rationality by virtue of being rational agents; therefore, rational moral principles apply to all rational agents at all times. Universalizability Kant's first formulation of the Categorical Imperative is that of universalizability: Kant defines maxim as a "subjective principle of volition," which is distinguished from an "objective principle or 'practical law. While "the latter is valid for every rational being and is a 'principle according to which they ought to act[,]' a maxim 'contains the practical rule which reason determines in accordance with the conditions of the subject (often their ignorance or inclinations) and is thus the principle according to which the subject does act. Maxims fail to qualify as practical laws if they produce a contradiction in conception or a contradiction in the will when universalized. A contradiction in conception happens when, if a maxim were to be universalized, it ceases to make sense, because the "maxim would necessarily destroy itself as soon as it was made a universal law." For example, if the maxim 'It is permissible to break promises' was universalized, no one would trust any promises made, so the idea of a promise would become meaningless; the maxim would be self-contradictory because, when universalized, promises cease to be meaningful. The maxim is not moral because it is logically impossible to universalize—we could not conceive of a world where this maxim was universalized. A maxim can also be immoral if it creates a contradiction in the will when universalized. This does not mean a logical contradiction, but that universalizing the maxim leads to a state of affairs that no rational being would desire. Kant believed that morality is the objective law of reason: just as objective physical laws necessitate physical actions