Current research on second-person relations has often overlooked that this is not a new topic. Addressed mostly under the heading of the “I–thou relation,” second-person relations were discussed by central figures of the phenomenological tradition, including Edmund Husserl and Martin Heidegger, but also quite extensively by much lesser-known authors, such as Karl Löwith, Ludwig Binswanger, and Semyon L. Frank, whose work has been undeservedly neglected in current research. This paper starts off by arguing that, in spite of the rightly acknowledged differences between the Husserlian and the Heideggerian approaches to the investigation of the social world, both approaches converge in the claim that the I–thou relation is founded on more basic forms of sociality. In a second step, against the background of Frank’s and Binswanger’s challenges to that claim, I argue that Löwith’s proposal that the I–thou relation is a primordial form of sociality can be vindicated by conceptualizing I–thou relations as close personal relationships (paradigmatically exemplified by companion friendships and romantic partnerships). After assessing how Löwith’s approach to the I–thou relation stands vis-à-vis Heidegger’s and Husserl’s views, I conclude by suggesting how Löwith’s approach can contribute to current research on second-person relations.