The concept of human nature is not dead in contemporary realist international-political theory; respective assumptions about the nature of Man are widespread. But ought human nature to be dead? The ought-question leaves us with two ideal-typical politico-theoretical options. To purify political realism from the tutelage of human nature, perfecting the Waltzians/Mearsheimerians. Or, alternatively, to bring back political realism to a more classical-style understanding of international-political theorizing defending proactively the concept of human nature, recognizing its virtues, making it the central concept upon which different political realisms are being built. In the preceding chapter, I unearthed the flaws and vices of much of human-nature criticism and argued that the sixfold set of the human-nature sins put forth by various strands of social and political philosophy is legitimate but represents, ultimately, merely a set of warnings that are too weak, too insufficient, and too unconvincing to make the overarching claim that the concept of human nature should not, must not, be used when theorizing the international-political. This marked the first step of the politico-theoretical plaidoyer in favor of classical-style political realism, of the intimate relationship between human nature and political realism.