In this essay, James Scott Johnston examines Jürgen Habermas's transcendental justification of his discourse theory of morality. According to Johnston, the application of Habermas's theory to educational issues often assumes that this justification is a cogent one. However, if the theory is to provide reasoned and appropriate guidance for educators, the justification of discourse ethics requires closer examination. Johnston argues that Habermas's so-called "weak" transcendental approach is in fact unsustainable because it fails to reconcile two conflicting schools of philosophical thought: Kant's transcendental idealism and George Herbert Mead's social pragmatism. Johnston concludes that a more plausible justification of the discourse ethical project can be achieved by rejecting Habermas's Kantianism and appealing solely to Mead's social pragmatic conception of rationality.