Immanuel Kant

Immanuel Kant was born as the fourth of nine children to Johann Georg Kant, a harness maker, and Anna Regina Reuter. His family was of modest means but deeply pietistic, a Lutheran movement emphasizing personal devotion and moral conduct. This religious upbringing profoundly influenced his later emphasis on duty and moral law. Königsberg was a cosmopolitan port city and intellectual center, part of the larger German Enlightenment. Kant would spend his entire life in this city, never traveling more than 100 kilometers from his birthplace, yet his ideas would travel around the world and transform Western philosophy.

Kant entered the Collegium Fridericianum, a prestigious Pietist school, largely through the influence of his mother and their pastor, Franz Albert Schultz. The strict discipline and religious instruction at this Latin school shaped his character, though he later recalled his years there with little fondness, finding the religious indoctrination excessive. The curriculum emphasized Latin, theology, and classical texts, providing Kant with a rigorous education in logic and rhetoric. Despite his reservations about the school's rigidity, it prepared him well for university studies and instilled in him a lifelong appreciation for discipline and systematic thinking.

Kant enrolled at the University of Königsberg, where he studied philosophy, mathematics, physics, and theology. His primary mentor was Martin Knutzen, a rationalist philosopher who introduced him to the philosophy of Christian Wolff and Leibniz, as well as to Newtonian physics. This exposure to both rationalist philosophy and empirical science would later inform his critical philosophy, which sought to reconcile the two approaches. During this period, his mother died in 1737, causing him great grief. Financial difficulties following his father's death in 1746 forced him to leave the university before completing his degree and work as a private tutor.

Kant completed his doctorate with a dissertation on fire and earned his habilitation with a thesis on the principles of metaphysical cognition. He began working as a Privatdozent (unsalaried lecturer) at the University of Königsberg, paid directly by student fees. For the next fifteen years, he taught a heavy load of courses covering metaphysics, logic, ethics, physical geography, anthropology, mathematics, and physics. Despite the grueling schedule—sometimes teaching up to 26 hours per week—this period allowed him to develop his ideas and refine his teaching methods. He became known as an engaging lecturer with a dry wit and became increasingly popular among students.

After repeatedly being passed over for professorships, Kant was finally appointed full professor of logic and metaphysics at the University of Königsberg. His inaugural dissertation, 'On the Form and Principles of the Sensible and Intelligible World,' marked an important transitional point in his thought. The position provided financial security and reduced his teaching load, giving him more time for research and writing. This appointment came after 15 years of precarious employment and marked the beginning of his most productive period. The freedom to pursue his philosophical investigations would lead to his revolutionary critical philosophy.

After more than a decade of intense work, Kant published the 'Critique of Pure Reason,' his magnum opus that revolutionized philosophy. The book sought to determine the limits and scope of human knowledge by examining the structures of human cognition itself. He argued that while all knowledge begins with experience, not all knowledge arises from experience—the mind actively structures our perceptions through innate categories. This 'Copernican Revolution' in philosophy attempted to reconcile rationalism and empiricism. Initially, the work received little attention and was considered difficult and obscure, but it would eventually be recognized as one of the most important philosophical works ever written, fundamentally reshaping metaphysics and epistemology.

Kant published the 'Groundwork of the Metaphysics of Morals,' laying the foundation for his ethical theory. In this concise but profound work, he introduced the concept of the categorical imperative, a universal principle for determining moral duties: 'Act only according to that maxim whereby you can at the same time will that it should become a universal law.' He argued that morality is based on reason rather than emotion or consequences, and that moral worth lies in acting from duty rather than inclination. The work also emphasized the inherent dignity of rational beings, who should never be treated merely as means to an end. This deontological approach to ethics profoundly influenced moral philosophy and remains central to ethical debates today.

Kant completed his second critique, the 'Critique of Practical Reason,' which provided a comprehensive account of his moral philosophy. Building on the Groundwork, this work explored the relationship between reason, freedom, and morality in greater depth. He argued that moral law provides proof of human freedom, as we can only be held responsible for our actions if we are free to choose. The work also addressed the postulates of practical reason: freedom, immortality, and God, which Kant argued we must assume for morality to make sense, even though they cannot be theoretically proven. This critique established the autonomy of ethics from theoretical knowledge and positioned morality at the center of human existence.

Kant completed his critical project with the 'Critique of Judgment,' which addressed aesthetics and teleology—beauty and purposiveness in nature. The work attempted to bridge the gap between the theoretical realm of nature (first critique) and the practical realm of freedom (second critique). He analyzed judgments of taste, arguing that aesthetic judgments are subjective yet universal, based on the free play of imagination and understanding. The work also examined our perception of design in nature and living organisms, though without committing to actual supernatural design. This third critique was influential in aesthetics and the philosophy of art, and revealed Kant's appreciation for beauty and the sublime, showing a less austere side to his philosophy.

Kant published his philosophical treatise on religion, which attempted to interpret Christian theology within the framework of rational morality. He argued that true religion is essentially moral, and that religious doctrines are valuable insofar as they promote moral improvement. The work emphasized the primacy of moral duty over religious ritual and institutional authority. His rational approach to religion, which stripped away much supernatural content, brought him into conflict with Prussian authorities. King Frederick William II's government issued an order forbidding Kant from writing or teaching on religious subjects, viewing his rationalism as a threat to orthodox Christianity. Kant complied during the king's lifetime, showing his respect for political authority even when he disagreed with it.

Kant wrote 'Perpetual Peace: A Philosophical Sketch,' his influential essay on international relations and peace. Written in the style of a diplomatic treaty, the work outlined conditions for establishing lasting peace among nations, including republican government, international federation, and cosmopolitan hospitality. He argued that perpetual peace is not just a lofty ideal but a moral necessity and rational goal. The essay anticipated many elements of modern international law and inspired the creation of organizations like the League of Nations and United Nations. His vision of a league of nations bound by international law and his emphasis on human rights and democratic governance remain influential in political philosophy and international relations theory.

Kant published 'The Metaphysics of Morals,' his comprehensive work on legal and ethical philosophy, divided into the Doctrine of Right (political philosophy and jurisprudence) and the Doctrine of Virtue (ethics). The work applied his moral philosophy to concrete issues of law, politics, and personal ethics. He developed theories of property rights, criminal punishment, international law, and civil society, arguing for the importance of individual rights and the rule of law. The Doctrine of Virtue addressed moral duties to oneself and others, covering topics from self-respect to beneficence. Though written when Kant's mental faculties were beginning to decline, the work provided practical applications of his abstract moral principles and influenced subsequent political and legal philosophy.

Kant died peacefully in Königsberg, the city he never left. His final years were marked by increasing mental and physical decline, likely due to dementia. His last words were reportedly 'Es ist gut' (It is good). He was given a grand funeral attended by thousands, reflecting his status as Königsberg's most famous citizen. He was buried in the Königsberg Cathedral, and his tomb became a place of pilgrimage. The epitaph on his grave quotes the famous concluding lines from the 'Critique of Practical Reason': 'Two things fill the mind with ever new and increasing admiration and awe, the more often and steadily we reflect upon them: the starry heavens above me and the moral law within me.' Kant left behind a philosophical legacy that transformed Western thought, establishing the foundations of German Idealism and profoundly influencing ethics, epistemology, metaphysics, aesthetics, and political philosophy.