Freedom and practical reason › Why the law is formal

A law grounded in a particular desired object would depend on a condition that need not govern every rational agent. One person wants comfort; another wants recognition. If the authority of the supposed moral principle depends on either object, its claim to universality becomes conditional.

Kant consequently looks to the form of lawgiving. The requirement is that the principle of an action be fit for universal legislation. This does not mean that deliberation takes place without circumstances. The maxim itself describes a proposed response to a situation. The formal requirement tests the principle's authority across agents, rather than turning a particular appetite into a universal command.

Imagine a rule allowing me to treat a commitment as binding only while it remains convenient. The objection is not merely that my friend would dislike the result. I must explain how I could claim the authority of an undertaking while refusing the condition that gives others reason to rely on it.

This example illustrates the kind of scrutiny the law invites. It is not a promise that every difficult case has an obvious verdict. Describing a maxim accurately can itself be difficult, and a misleading description can conceal the feature that deserves examination. A universalization test applied to a carefully sanitized maxim may miss what the person is actually doing.