Question

I saw that there was a Haredi person here who asked about military enlistment, and you answered him that he has an obligation to enlist by virtue of the categorical imperative. On the face of it, the logic of the imperative is simple, but it makes me wonder whether there are objections to the categorical imperative. After all, seemingly, if a person says that his action will not affect anyone else at all—such as enlistment or tax evasion—and he is not acting as part of a collective ideology but on the basis of his own personal choice, then it is hard to argue that there is a moral obligation to do something, because it is clear that he is acting as an individual and not as part of a collective. Is that considered a kind of objection to the imperative?