Between 'Indubitably Certain' and 'Quite Detrimental' to Philosophy: Kant on the Guise of the Good Thesis

Kant clearly endorses some version of the 'old formula of the schools', according to which all volition is sub ratione boni. There has been a debate whether he holds this only for morally good actions. I argue that a closer look at the distinction between the good and the agreeable does not support this conclusion. Considering Kant's account of the detrimental and the correct use of this thesis, I argue that rational beings always will sub ratione boni, even when they act immorally, because they act on principles. I argue that Kant's accounts of self-love and self-conceit support this view.