The concept of “spirit,” foundational for Montesquieu’s political science, is key to his understanding of the knowledge and prudence of statesmanship. Yet, although the importance of spirit to Montesquieu’s thought is widely acknowledged, the concept rarely receives the extended treatment that it warrants. In this essay, first, I explicate the meaning of spirit in light of Montesquieu’s description of the divided sovereignty of human life, expressed in his observation that “many things govern men.” For Montesquieu, spirit refers to how various factors govern or rule human beings, together forming what we might call the national or civic character, collective consciousness, or social mind of a society. Second, I examine how the concept of spirit is connected to Montesquieu’s understanding of human nature as flexible within limits. Third, I draw out the implications of spirit for the practice of statesmanship.