After the failure of Beethoven's opera Fidelio, oder die eheliche Liebe in 1805, a series of reviews criticized the dramatic layout of the opera and Beethoven's musical setting. Much of the critical response to the first version focuses on an incongruity between the opera's first two acts and its final act. This incongruity manifested itself above all in the suddenness with which the bourgeois marital fantasies of the character of Marzelline gave way to the marital ideals of Leonore in the final act. The duet “O namenlose Freude!” was singled out along these lines for failing to achieve an appropriate musical characterization. Beethoven revised the opera for a production in early 1806 that was much more successful. The revisions he made in the 1806 version are almost always understood as rushed solutions to the most serious problems posed by the original version of the opera. Yet the fact that many of the more elaborate revisions survived until the final version of 1814 suggests that Beethoven and his collaborators did not simply act in haste. As the opera's climactic expression of marital love, “O namenlose Freude!” offers a particularly revealing window on how his ideas about marriage motivated the revision process. In this article I propose a new reading of the 1806 Leonore based on the critical reception of the opera's first performances of 1805 and an examination of ideas about marital love at the turn of the nineteenth century.