Kant helps us understand the conditions for peace by reminding us that lasting peace requires both cosmopolitan legal reform and individual moral improvement, including resistance to egoism and the cultivation of cosmopolitan attitudes. The duty to pursue peace includes the duty to promote the rule of domestic and international law and work against its unilateral subversion. The juridical cosmopolitanism of a worldwide league of free peoples enables resistance to the dangers posed by authoritarian regimes and their dangerous willingness to manipulate their subjects and ignore international law. Constraining egoism enables people to overcome the tyranny of their desires and cultivates a sense of affiliation with the larger community of humanity in general, providing the moral foundation needed to support a cosmopolitan legal order. Moral development to a great extent is fostered through the arts and humanities, and a robust cultural life therefore ought to play a central role in the pursuit of global peace.