 The main challenge which Parfit presented in his celebrated work Reasons and Persons is to develop a theory of beneficence—theory X he calls it—which is able to solve the Non-Identity problem, which does not lead to the Repugnant Conclusion and which thus manages to block the Mere Addition Paradox, without facing other unacceptable conclusions. However, Parfit’s own conclusion was that he had not succeeded in developing such a theory.