Regarding to the numbers of Categorical Imperative, many Kantians make the response, for example, Nuyen supports the most widely accepted Paton’s view: there are five or more formulations. In my thesis, I will mainly analyze three main formulations and talk about formulation of autonomy in the last chapter. See A. T. Nuyen Counting the Formulas of the Categorical Imperative: One Plus Three Makes Four of formulation Like the challenge raised by Benjamin Constant in 1797, Kant responded in a short essay On a Supposed Right to Lie from Philanthropy. Constant’s charge is basically around Kant’s moral principle ‘duty to tell the truth’ would, if taken unconditionally and singly, make any society impossible. The further discussion on Kant’s standpoint and strategy please see Helga Varden’s discussion on the case of Kant and Lying to the Murderer at the Door in Kant 's Legal Philosophy and Lies to Murderers and Nazis. Precisely, Mill claims the Categorical Imperative, is actually a disguised version of the utilitarian principle, Mill says ‘‘This remarkable man… does… lay down a universal first principle as the origin and ground of moral obligation; it is this: — ‘So act, that the rule on which thou actest would admit of being adopted as a law by all rational beings’. But when he begins to deduce from this precept any of the actual duties of morality, he fails, almost grotesquely, to show that there would be any contradiction, any logical (not to say physical) impossibility,