Doing as one pleases, or governing oneself?
On the axis: Freedom of the will · the law one gives oneself
Is being free to do what one feels like in the moment, or to govern oneself, at the risk that whoever follows their every desire becomes its slave?
Justification
The third antinomy sets a seamless against the demand for a free causality, and both theses seem equally provable. Kant resolves it through the distinction: determinism governs the human being as phenomenon, yet nothing forbids thinking him a cause at the noumenal level. The moral law requires it: "you ought" implies "you can", so freedom is a fact of practical reason. Hence the explicit rejection of (a wretched subterfuge); but since freedom stays noumenal, never observed in the world, the score stops short of the extreme.
Critique of Pure Reason, Third Antinomy · Critique of Practical Reason
Justification
Inclinations are not evil in themselves, but they cannot ground moral worth: an action has value only when done from duty, independently of any inclination. This moral disinterestedness requires that the will make itself autonomous with regard to desire, acting against it where need be; without preaching the extinction of inclinations, Kant keeps a distance from them that leans toward detachment more than toward their eudaimonist sorting.
Groundwork of the Metaphysics of Morals, I-II · Critique of Practical Reason
Justification
The appetites form the lowest part of the soul and must be mastered and curtailed under reason's guidance, for a soul given over to its desires becomes a "leaky jar" that nothing can fill. Plato preaches not the extinction of desire but its redirection: sublimated erōs becomes the drive that carries the soul toward the Beautiful and the Good.
Gorgias, 493a-494a · Republic, IX, 571a-580a
leads to: Relation to desire (The hierarchy of desires)