After shortly outlining what can be called hermeneutics of love, the author carries out a brief interpretation of a poem written by Heinrich Heine from the perspective of Alain Badiou’s theory of love. For this purpose, and after analyzing the structure and content of Heine’s poem itself, the author synthetizes and formalizes four different conceptualizations of love as explained by Badiou in a lecture from 2006 (Mexico City). The author finally uses the conceptual background of Badiou’s proposal to re-interpret Heine’s poem and to show that Heine’s poem offers another key concept missing in Badiou’s theory for the understanding of the experience of love, i. e. the concept of sincerity (Aufrichtigkeit).