Perpetual Peace: A Philosophical Sketch

Immanuel Kant (1724-1804) was a German philosopher who spent his life in Königsberg, or modern-day Kaliningrad. Kant’s parents were devout members of the Pietist branch of the Lutheran denomination. They raised Kant under the doctrine that religion is expressed internally through obedience and morality. His parents’ involvement in the church afforded Kant the opportunity to attend a Pietist school, where he learned about Latin classics. In 1740, Kant attended the University of Königsberg, where he studied theology. However, his attention was soon diverted by mathematics, physics, and philosophy. Although he grew up in a strictly religious household, Kant did not profess a particular faith as an adult. Instead, he explored how humans might replace religion with reason.

Kant’s life was remarkably consistent and disciplined. He was famous for his punctuality, to the point that his neighbors were said to set their clocks by his daily walks. Although he had several more lucrative offers, Kant stayed in Königsberg, living frugally—just as he preferred. After spending time as a private tutor, Kant finally landed a salaried position at the University of Königsberg in his 50s. His daily routine included waking at five in the morning, writing for three hours, lecturing for four hours at his alma mater, eating lunch at the same restaurant, walking along the same route of a park, and returning home at the same time each day. This rhythm reflected both his temperament and his philosophical preference for order, rationality, and moral self-governance. Despite his local life, Kant’s intellectual reach was vast, extending across Europe through correspondence and publication.

This rigidity was indicative of Kant’s position within the Enlightenment. The philosopher believed that human nature was marked by a compulsion toward selfishness and passion. Reason was a ruling principle which guided one toward morality. Kant applied rationality to every part of his life, maximizing his time through discipline. In his view, freedom is the expression of the rational self—the self that acts in accordance with the categorial imperative. This liberty is lost when humans succumb to their passions and let them rule. By the time Kant wrote Perpetual Peace, he had already detailed his moral philosophy in the Groundwork of the Metaphysics of Morals. His account of duty, autonomy, and the categorical imperative informs Kant’s political prescriptions.

Kant believed that the categorial imperative applied to states as well as the individual, and that the primary role of the government is to preserve human liberty. He considered the governing state the external expression of this moral obligation. Zum ewigen Frieden, or Perpetual Peace, was published in 1795. Kant wrote his political framework in the aftermath of the French Revolution and at the dawn of the Napoleonic era, a period of intense European warfare and political change. The immediate historical context—debates about revolution, sovereignty, nationalism, and the reshaping of European states—is central to the essay’s concerns.

Throughout his works, Kant argues that humanity lives according to universal laws of nature which are subject to reason and morality. These laws form the structure of human experience. In Perpetual Peace, the philosopher applies these same moral principles to international relations, envisioning a federation of free, republican states governed by law rather than violence. For Kant, lasting peace cannot be secured through temporary treaties or pragmatic alliances. Instead, peace must be grounded in moral duty. Kant’s ideas have since proven enormously influential: Thinkers like Hannah Arendt, G.W.F. Hegel, and Arthur Schopenhauer have credited Immanuel Kant as an influence, and his political theories have formed the foundation for modern developments like the establishment of the United Nations.