Felicité de Lamennais was born at Saint-Malo in Brittany, the son of Pierre Robert de Lamennais (or La Mennais), a ship-owner ennobled by King Louis XVI for public services, and Gratienne Lorin. Lamennais lost his mother at the age of five and as a result, he and his brother Jean-Marie were sent for education to an uncle, Robert des Saudrais at La Chênaie, an estate near Saint-Malo. He spent long hours in his uncle's library, devouring among other things the writings of Rousseau, Pascal. He thereby acquired a vast and varied learning, which influenced his subsequent career.
Of a sickly and sensitive nature, and shocked by the events of the French Revolution, he developed a morbid frame of mind, which characterized him throughout all his changes of opinion and circumstance. He at first held rationalistic views, but partly through the influence of his brother Jean-Marie and partly as a result of his philosophical and historical studies, he felt faith to be indispensable to action and saw religion as the most powerful leaven of the community. He voiced these convictions in the Réflexions sur l'état de l'église en France pendant le 18ieme siècle et sur sa situation actuelle, published anonymously in Paris in 1808, which eagerly recommended religious revival and active clerical organization and awakening the ultramontane spirit. Napoleon's police deemed the book dangerously ideological and tried to suppress it.
Lamennais devoted most of the following year to translating Louis de Blois Speculum Monachorum into French, which he published in 1809 under the title Le Guide spirituel (1809).
Though his father had intended him the career of a merchant, Lamennais received the tonsure in 1811 and shortly afterwards became professor of mathematics in an ecclesiastical college founded by his brother at Saint-Malo.
In 1814 he published, with his brother, De la tradition de l'église sur l'institution des éveques (1814), in which he strongly condemned Gallicanism and the interference of political authority into ecclesiastical matters. This book was occasioned by Napoleon's nomination of Jean Siffrein Maury as Archbishop of Paris, according to the provisions of the Concordat of 1801.
Lamennais hailed the first Bourbon restoration, which he witnessed in Paris, with satisfaction, less as a monarchist than as a strenuous apostle of religious regeneration. During the Hundred Days, he escaped to London, where he obtained a poor living by giving French lessons in a school founded by the Abbé Jules Carron for French émigrés; he also became tutor at the house of Lady Jerningham, whose first impression of him as an imbecile changed into friendship. After the final overthrow of Napoleon in 1815 he returned to Paris and in 1816 he was ordained a priest by the Bishop of Rennes, yielding to his brother's and Carron's advice despite misgivings as to his calling.
The first volume of his great work, Essai sur l'indifference en matière de religion, appeared in 1817, and affected Europe like a spell, investing, to quote Lacordaire, "a humble priest with all the authority once enjoyed by Bossuet". Lamennais denounced religious indifference by the state; he contended that private judgment, introduced by Martin Luther into religion, by Descartes and Leibniz into philosophy and science, and by Rousseau and the Encyclopaedists into politics, had resulted in practical atheism and spiritual death, and proclaimed ecclesiastical authority, founded on the absolute revelation delivered to the Jewish people, but supported by the universal tradition of all nations, to be the sole hope of regenerating the European communities.
Three more volumes (Paris, 1818-1824) followed, and met with a mixed reception from the Gallican bishops and monarchists, but with the enthusiastic adhesion of the younger clergy. The work was examined by three Roman theologians, and received the formal approval of Pope Leo XII. Lamennais visited Rome at the pope's request, and was offered a place in the Sacred College, which he refused.
Lamennais also published works of piety, e.g. a widely-read French version of the "Imitation of Christ" with notes and reflections (1824), the "Guide du premier âge", the "Journée du Chrétien", and a "Recueil de piété" (1828). The failure of a publishing house aimed at spreading this pious literature resulted in Lamennais' own financial ruin.
On his return to France he took a prominent part in political work, and together with Chateaubriand and the Comte de Villèle, was a regular contributor to the Conservateur. However, when Villèle became the chief supporter of absolute monarchy, Lamennais withdrew his support and started two rival organs, Le Drapeau blanc and Le Mémorial catholique. He criticized the 1825 Anti-Sacrilege Law introduced by Villèle's administration in a pamphlet. Various other minor works, together with De la religion considérée dans ses rapports avec l'ordre civil et politique (1825-1826), kept his name before the public.
He retired to La Chênaie and gathered round him a host of brilliant disciples, including Montalembert, Lacordaire and Maurice de Guérin. His principle object was to create an organised body of opinion to campaign against Gallicanism, the control and influence of the state in church matters, and espoused ultramontanism.
He adopted a frank and bold attitude, which was further strengthened by his medical record: as his s health broke down, he went to the Pyrenees to recover, but on his return to La Chênaie in 1827 he had another dangerous illness. His recovery impressed on him the thought that he had only been dragged back to life to be the instrument of providence. Les Progrès de la revolution et de la guerre contre l'église (1828) marked Lamennais's complete renunciation of royalist principles, and henceforward he dreamt of the advent of a theocratic democracy.
Lamennais founded L'Avenir, the first number of which appeared on October 16 1830, with the motto "God and Liberty." From the first the paper was aggressively democratic, demanding rights of local administration, an enlarged suffrage, separation of church and state, universal freedom of conscience, instruction, assembly, and the press. Methods of worship were to be criticized, improved or abolished in absolute submission to the spiritual, not to the temporal authority. With the help of Montalembert, he founded the Agence generale pour la defense de la liberté religieuse, which became a far-reaching organization, it had agents all over the land who noted any violations of religious freedom and reported them to headquarters. As a result, L'Avenir's career was stormy and its circulation opposed by conservative bishops.
In response, Lamennais, Montalembert and Lacordaire suspended their work and in November 1831 set out to Rome to obtain the approval of Pope Gregory XVI. After much opposition, they were received in audience, but only on the condition that the object which brought them to Rome should not be mentioned. This was a bitter disappointment to such earnest ultramontanes, who a few days later received a letter from Cardinal Pacca, advising their departure from Rome and suggesting that the Holy See, whilst admitting the justice of their intentions, would like the matter left open for the present.
While Lacordaire and Montalembert immediately left, Lamennais stayed on until Gregory's letter to the Polish bishops, which denounced the Polish revolution against the Tsar, dashed his last hopes. While staying in Munich, Lamennais received the 1832 encyclical Mirari vos, which condemned religious pluralism in general and, without naming Lamennais, certain of the ideas advanced in L'Avenir. After this, Lamennais and his two lieutenants declared that out of deference to the pope they would not resume the publication of L'Avenir and dissolved the Agence.
Lamennais retired to La Chénaie, deeply wounded by the opposition of those for whom he had fought. His resentment reached the world through his correspondence. On being informed about this, the Vatican demanded frank and full adhesion to the encyclical Mirari vos. Lamennais refused to submit without qualification and in December 1833 renounced his ecclesiastical functions and finall abandoned all external profession of Christianity, focusing instead on the amelioration of humanity, devotion to the welfare of the people and of popular liberties.
In May 1834, he penned Paroles d'un croyant (1834), a tractace of aphorisms whose apocalyptic diction cried out against the established social order and loudly declared his rupture with the Church. In the Encyclical Singulari nos, Gregory XVI condemned the book as "small in size, but immense in perversity" and censured Lamennais' philosophical system.
Lamennais was increasingly abandoned by his friends and in 1837 published Les Affaires de Rome, des maux de l'église ci de la société, in which he related his perspective on his relations with Gregory XVI.
After this, he penned several articles in the Revue des Deux Mondes, the Revue du Progrès and Le Monde and published the pamphlets Le Livre du peuple (1837), De l'esclavage moderne (1839), Politique a l'usage du peuple (1839), Discussions critiques (1841), Du passé et de l'avenir du peuple (1841), Amschaspands et Darvands (1843), in which he espoused popular sovereignty and rails against society and public authorities. After the publication of Le Pays et le gouvernement (1840) he was imprisoned for a year in 1841.
From 1841 to 1846, he published the four-volumed Esquisse d'une philosophie, a treatise on metaphysics, which show his departure from Christianity. The third volume, which is an exposition of art as a development from the aspirations and necessities of the temple, stands pre-eminent. Lamennais also published Les Evangiles, a French translation of the Gospels with added notes and reflections.
In 1846, he published Une voix de prison, written during his imprisonment and an interesting contribution to the literature of captivity.
Lamennais sympathized with the Revolution of 1848 and was elected a deputy for Paris in the Constituent Assembly. He drew up a plan for a Constitution, which was rejected as too radical. After this, he confined himself to silent participation in the sessions. He also started the newspapers Le Peuple constituant and La Révolution démocratique et sociale, espousing radical revolution. Both papers quickly ceased publication. He also was named president of the Société de la solidarité républicaine. He remained a deputy in the legislative assemblies until Napoleon III's 1851 coup, which caused Lamennais' relapsing to misery and isolation.
After 1851, he occupied himself with La Divine Comédie, a translation of Dante's Divine Comedy and refused several attempts to reconcile him to the Church. He died in Paris in 1854 and was buried according to his own directions at Père Lachaise without funeral rites, being mourned by political and literary admirers.
There are two Œuvres complètes de Lamennais in ten volumes, the first published in 1836-1837, the second published in 1844, but despite the name both are incomplete.