Categorical Imperative; Onora O'Neill

"In restricting our maxims to those that meet the test of the categorical imperative we refuse to base our lives on maxims that necessarily make our own case an exception. The reason why a universilizability criterion is morally significant is that it makes our own case no special exception (G, IV, 404). In accepting the Categorical Imperative we accept the moral reality of other selves, and hence the possibility (not, note, the reality) of a moral community. The Formula of Universal Law enjoins no more than that we act only on maxims that are open to others also." (Onora O’ Neill, Constructions of Reason: Explorations of Kant’s Practical Philosophy (New York: Cambridge University Press, 1989), 156p.)