As will be explained below, Reinach’s treatment of promises transcends mere private intentions. A promise, he argued, is a binding act that establishes a social relationship. When we make a promise, we address someone else, and their acknowledgment completes the act. The act of promising establishes a social relationship and carries legal implications. Reinach’s insights prompt us to delve more deeply into the problem of immoral promises and the role of immorality both in the sphere of legal a priori and in the realm of positive legality. As a case study, we turn to the contentious issue of surrogacy contracts. These agreements, often morally charged, exemplify the complex interplay between promises, morality, and legal validity.