L'anima del filosofo, ossia Orfeo ed Euridice, Hob. 28/13, is an opera in Italian in four acts by Joseph Haydn and is one of the last two operas written during his life, the other being Armida (1783).The libretto, by Carlo Francesco Badini, is based on the myth of Orpheus and Euridice as told in Ovid's Metamorphoses. Composed in 1791 for His Majesty's Theatre during his first visit to England, the opera was never performed during Haydn's lifetime and only given its formal premiere in 1951.