 Bolzano’s main objection against the Categorical Imperative was that we cannot derive from it alone — as Kant supposed — whether a given act ought to be done or not. Kant’s instruction to ask ourselves of a maxim whether we can will without contradicting ourselves that it should become a universal law is of no use, according to Bolzano, since for him there is no practical proposition or ought proposition whose contradictory opposite is self-contradictory. This, however, is not a decisive argument against Kant’s Categorical Imperative for several reasons. Nevertheless, Bolzano refused to accept the Categorical Imperative strictly and replaced it with the utilitarian principle of “the advancement of the general welfare”, as he proudly reports in his autobiography (Bolzano 1836, 23).