Louis Lambert is a largely autobiographical philosophical novel, devoted to the tragic destiny of a genius whom the very power of his thought leads to madness. The narrator evokes his childhood friend, Louis Lambert, a prodigy of intelligence met at the Collège de Vendôme — the establishment where Balzac himself was a pupil. From his earliest years, Louis Lambert manifests extraordinary intellectual faculties: a voracious, mystical, speculative mind, he devours books, elaborates metaphysical theories on the nature of thought, will, and spirit, and undertakes the writing of a vast Treatise on the Will, in which he seeks to found a science of the soul and to penetrate the secrets of mental and spiritual life. But this superhuman intelligence, this constant tension toward the absolute and the invisible, finally consumes him. The power of his inner life gradually detaches him from the sensible world; he sinks into a kind of catalepsy and mystical dementia, withdrawing into a state close to ecstasy or annihilation, which can be read either as madness or as access to a higher spiritual reality, inaccessible to ordinary men. Taking refuge in silence and immobility, watched over by the woman who loved him, Louis Lambert lives his last years as a being half-detached from matter. Balzac develops his theory of spiritual energy, according to which thought is a material force that, in excess, destroys the organism: genius dies of its own fire. The novel, nourished by Swedenborgian mysticism and reflections on magnetism and the will, is one of the author's most personal and speculative texts. Louis Lambert meditates on genius, madness, and the angelism of the spirit, and illustrates the great Balzacian law of thought that kills.