Martin Buber and Emmanuel Levinas—two of the most prominent Jewish thinkers of the 20th century—both refused to conceive of one’s relation to the other in purely cognitive terms. They differed, however, in their characterization of the structure and nature of the intersubjective encounter. Whereas Buber emphasized the horizontal and reciprocal character of the I-Thou relation, Levinas insisted that the relation between self and other is in the first instance a vertical relation of responsibility. In the following contribution, we will present and analyze the disagreement between Buber and Levinas and assess to what extent their exchange might be relevant for contemporary debates on second-person engagement.