Why did Jules Laforgue insert among his Complaintes the older poem « Litanies de mon triste coeur » (the Litanies of my sad heart) under the title « Complainte-Litanies de mon Sacré-Coeur » (The Complaint-Litanies of my Sacred Heart) ? Can a trivial variation lead to questions about the history and the mentality of an entire period ? Yes, if the issue is the growing idolisation of the Heart of Jesus, inseparable from the Roman issue, and which, at the time, mobilised literature, religion, songs,... This is the opportunity to read once again certain well-known lines from Baudelaire and Verlaine, as well as a number of pages from Michelet, Ernest Hello or Huysmans. Although the poet of the Complaintes is a dilettante, it can nevertheless be asked of him whether he is sacrilegious in respect to orthodox Catholicism and the pieties of the people as they manifest themselves. This collective veneration was testified to materially by its imposing building, the new basilica of the Sacred Heart in Montmartre, or basilique du Sacré-Coeur de Jésus.