In this paper the French socialist Eugène Fournière studies the very original moral theory of the first French socialists, from Saint-Simon to Proudhon. Its main sources are the sensualism, utilitarianism, and materialism it originated from the French Revolution. However Fournière suggests to interpret it as a kind of “sympathetic utilitarianism,” proposing to reverse classical utilitarianism in order to articulate self-love and love for others, individual freedom, and social solidarity. By the way, this socialist moral idealism seems to be very close to Jean-Marie Guyau’s “No moral obligation no sanction.”