This article reevaluates the political dimension of the work of Mesmer, showing the involvement of the founder of animal magnetism in the conflicts of his time. The first part of the article is devoted to his action during the Revolution. During his stay in the Austrian capital between 1790 and 1793, Mesmer played an important role in the ’jacobin plot’’ of Vienna. His return to Paris in 1798 marked his return to the political scene. Mesmer attempted at this time, without any success, to make his conceptions known to the public not only his doctrine of animal magnetism, but also his theories about the nature of man and organization of society. These ideas were finally published in German translation in 1814, and greeted with general indifference. The second part of the article, focusing on the period before the Revolution, examines the genesis of Mesmer’s political and moral ideas; these were developed in stages, even if his doctrine of animal magnetism still appeared confined to the medical sphere. Born within the framework of Viennese medicine, influenced by enlightened despotism, Mesmer’s ideas took a critical turn during his stay in Paris, when animal magnetism became a public passion. It was then that the unifying theme of harmony developed as an essential part of the doctrine of animal magnetism. Finally, the last part of the article investigates the precise content of Mesmer’s moral and political theories, as these were expressed first in the lessons of 1784, then expanded in his later publications.