In this dissertation, I attempt to convince an audience of modern naturalists that Socrates’ famous moral thesis—that we should prefer to suffer injustice rather than inflict it, because it is impossible for an unjust person to be happy—is true. Rather than logical proof, however, I focus on questions of rhetoric and of spiritual practice. In short, I argue that the existential truth of Socrates’ claim only begins to manifest for those who adopt a particular curriculum of spiritual training, which combines the pursuit of moral goodness with the pursuit of self-knowledge; this training, however, needs to be undertaken under the aegis of a philosophical rhetoric that first opens us to at least the possibility that Socrates might be right. In the first two chapters of this dissertation, therefore, I focus on rhetoric, as the attempt to destabilize the common naturalist confidence that their own scientific worldview is grounded on the true nature of reality, and that this unprecedented understanding shows Socrates’ moral thesis to be nonsense. Following this, from chapters three to five, I present the aforementioned spiritual curriculum: the “spirituality from above,” oriented towards moral goodness, in contradistinction to the “spirituality from below” that is oriented toward self-knowledge. After presenting the logic of this bivalent practice in chapter three, I then explicate it with reference to the philosophies of David Hume and Richard Rorty (chapter four), and then Plato and Nietzsche (chapter five). Finally, in chapter six, I consider what accepting the truth of Socrates’ moral thesis would mean for the way we live our everyday lives, under conditions of peace, in which the question of whether to suffer or inflict injustice will likely not be a pressing existential concern, and the question of what it actually means to be just will always be unclear and disputed.