In the last years, ethical discourse has entered in public life. It is expected from ethics to bring about the reforms and the new ideas which politics is needing. The author of this article wonders about the role ethics has to play in front of the political shortcomings. Therefore, she goes to Rawls philosophy and specially to his last book, Political Liberalism, where a central place is given to the concept of reasonability as the basis of the political conception of the person. Reasonability means responsibility, an usual concept both in political and moral theories, but nonetheless fundamental in order to put ethics in its right place, as the impulse of good politics.