 Kant’s first formulation of the CI states that you are to “act only in accordance with that maxim through which you can at the same time will that it become a universal law” (G 4:421). O’Neill (1975, 1989) and Rawls (1980, 1989), among others, take this formulation in effect to summarize a decision procedure for moral reasoning, and we will follow their basic outline: First, formulate a maxim that enshrines your proposed plan of action. Second, recast that maxim as a universal law of nature governing all rational agents, and so as holding that all must, by natural law, act as you yourself propose to act in these circumstances. Third, consider whether your maxim is even conceivable in a world governed by this new law of nature. If it is, then, fourth, ask yourself whether you would, or could, rationally will to act on your maxim in such a world. If you could, then your action is morally permissible.