Does Kant’s maxim ‘ought-implies-can’ apply if the principle of alternate possibilities does not?

Frankfurt?s critique of the principle of alternate possibilities led to a reexamining of many of the conditions that were rooted in the principle. One of these includes Kant?s famed maxim ?Ought-implies-can?. Since the alternate possibilities principle underscores the condition that is required for the subject to be morally responsible (could have done otherwise condition), the maxim also implies the condition?s validity also in situations where it is met and provides the basis for the attributiveness of morally relevant qualities. Although Frankfurt?s example showed that the presence of moral responsibility does not require the validity of the alternate possibilities principle - the condition of the possibility of acting differently need not be met - then even the attributiveness of moral qualities, in the way that the maxim implies, cannot be applied in situations where the subject is responsible, even though they could not have done otherwise. Frankfurt, however, refuses to draw this conclusion and believes that even under the conditions set forth, the maxim can apply. The provocative claim challenges Frankfurt-type compatibilists, and the paper examines whether it is founded, in addition to what consequences can be drawn pertaining to Kant?s maxim?s validity. The conclusion - contrary to Frankfurt?s initial optimism - is that in a world where causal determinism applies and where the alternate possibilities principle does not, although the subject may be morally responsible, their responsibility cannot be grounded in deontological reasoning.