  The argument excited almost as much skepticism as attention. It seemed implausible that the very activity of prescribing universally should commit a speaker to a substantive ethical position, let alone one so distinctive. However, the logic of Hare’s position became perspicuous in his third book, Moral Thinking: Its Levels, Method, and Point (1981). It is there set out as follows. In wondering whether he should assent to the statement “A ought to φ”, the speaker has to reflect whether he can prescribe that everyone should act in the same way, whatever his own situation.  “I” connotes no essence (e.g., human): each of us might be anything, and so has, when prescribing for all situations, actual or possible, to be concerned on behalf of everybody. There is further a prescriptive aspect to the meaning of “I”: to take a role to be possibly one’s own, and to prescribe for that possible situation, is to give weight to the preferences of the occupant of that role as if they were actually one’s own. Hence, the speaker can rationally assent to a particular “ought”-statement only if it is derivable from some universal principle that he will accept if he gives impartial and positive weight to all preferences whose satisfaction would be affected by its observance. Thus moral reflection generates a universalized prudence. Moral ideals register within this framework simply as universal preferences; to allow one’s own ideals to override more intense or prevalent desires or ideals of others is a kind of egoism, and so excluded. Human decision remains free, however rational and informed, because anyone can avoid the constraints of morality by declining to moralize; for this reason, it remains true that no “is” entails an “ought”.