His education was carefully conducted by his father, and the early perusal of Buffon's Natural History (Histoire naturelle, générale et particulière) awakened his interest in that branch of study, which absorbed his chief attention.

His leisure he devoted to music, in which, besides becoming a good performer on the piano and organ, he acquired considerable mastery of composition, two of his operas (which were never published) meeting with the high approval of Gluck; in 1781–1785 he also brought out in two volumes his Poétique de la musique.

[1] After the French Revolution Lacépède became a member of the Legislative Assembly, but during the Reign of Terror he left Paris, his life having become endangered by his disapproval of the massacres.

During the latter part of his life he wrote Histoire générale physique et civile de l'Europe, published posthumously in 18 volumes, 1826.

After the Revolution, he helped Cambacérès to rebuild a French freemasonry submitted to the Emperor, and joined "Saint-Napoléon" lodge where General Kellermann was worshipfull master.