Second-personal ethics, as developed by Stephen Darwall and others, seeks to ground morality not in abstract principles but in authoritative, intersubjective claims. Darwall draws significant influence from Johann Gottlieb Fichte’s Summons Argument in his 1798 System of Ethics. As a transcendental philosopher, Fichte argues that ethics is rooted in the very structure of subjectivity, contending that a moral community with shared norms is a necessary precondition for self-consciousness. Fichte, however, gave this argument in several works and I argue that a stronger foundation for second-personal ethics lies in the 1799 version of the Summons Argument, found in Fichte’s Wissenschaftslehre nova methodo. I reconstruct this version of the argument with an eye towards grounding second-personal moral claims.