Jean François, Marquis de Chastellux and Claude Helvétius exemplify perhaps better than any other writers the specific flavour of utilitarianism in pre-revolutionary France. Both were deeply committed to the improvement of the condition of the poor and believed that governments had a duty to foster the general good; both thought that, as Helvétius put it, ‘wise laws would be able without doubt to bring about the miracle of a universal happiness’ (Helvétius 1774:187).3 For these writers, as for others of their compatriots, utilitarianism was primarily a political philosophy and less a theory of personal morality. Further, it was a philosophy which offered what seemed to them a clear-cut and highly practical recipe for political action: governments should first of all find out what makes people happy, then devise appropriate social strategies to bring that happiness about. Subsequent experience of well-meant but often disastrous social experiments from 1789 to the fall of communism may make us question how straightforward this programme really was; but nothing can destroy the credit of the philosophes for promulgating it, at considerable personal risk, in the France of the ancien régime.