Immanuel Kant

Immanuel Kant (22 April 1724 – 12 February 1804) was a German philosopher and one of the foremost figures of the Enlightenment. His extensive contributions to epistemology, metaphysics, ethics and aesthetics have made him one of the most influential thinkers in the history of Western philosophy. Kant’s work sought to resolve long-standing disputes between rationalist and empiricist traditions, and his philosophical system fundamentally reshaped modern thought.
Kant’s doctrine of transcendental idealism held that space and time are forms of intuition through which the mind structures experience, and that objects of experience are appearances rather than things as they are in themselves. Attempting to address scepticism concerning the possibility of knowledge, he elaborated this view most famously in the Critique of Pure Reason (1781, revised 1787). Kant proposed that objects conform to the categories and forms of human cognition, drawing a parallel with the intellectual shift prompted by the Copernican Revolution. His moral philosophy centred on the authority of reason and the concept of duty, while his aesthetics emphasised disinterested judgment. Kant’s religious views were closely linked to his ethical theory, though their interpretation remains debated. In political philosophy he envisaged the achievement of lasting peace through republican government and cooperative international institutions, yet his legacy is complicated by the scientific racism he endorsed for much of his career before revising his views late in life.

Early Life

Kant was born in Königsberg, East Prussia, into a German Lutheran family. His mother, Anna Regina Reuter, was of Nuremberg ancestry, and his father, Johann Georg Kant, was a harnessmaker who had moved from the Baltic city of Klaipėda. Some scholars have proposed that the family name originated from the village of Kantvainiai in present-day Lithuania and may have Kursenieki connections.
Baptised Emanuel, Kant later altered the spelling to Immanuel after studying Hebrew. He was the fourth of nine children, six of whom survived to adulthood. Kant’s childhood was shaped by the values of Pietism, emphasising devotion, humility and strict moral discipline. His early schooling focused heavily on Latin and religious instruction, with comparatively little emphasis on mathematics or natural science. Throughout his life Kant maintained a rigid daily routine, becoming a well-known figure for his famously punctual walks. Although he considered marriage at least twice, he never married, but enjoyed an active social and intellectual life in Königsberg.

Young Scholar

Kant attended the Collegium Fridericianum, completing his studies in 1740, and that same year entered the University of Königsberg, where he would ultimately spend his entire academic career. He studied under Martin Knutzen, an associate professor of logic and metaphysics, who introduced him to the writings of Leibniz and Wolff as well as developments in British philosophy and Newtonian physics. Knutzen steered Kant away from doctrines such as pre-established harmony and traditional idealism, views widely regarded with suspicion in eighteenth-century thought. Kant later developed his own philosophical position partly in opposition to these earlier forms of idealism.
His studies were interrupted following his father’s death in 1746, after which he worked as a private tutor in the region surrounding Königsberg, continuing his research independently. His first philosophical publication appeared in 1749 under the title Thoughts on the True Estimation of Living Forces, reflecting his early engagement with debates in natural philosophy.

Early Work and Scientific Interests

Although best known for his later philosophical writings, Kant made notable early contributions to several scientific fields. In 1754 he responded to a question posed by the Prussian Academy of Sciences concerning Earth’s rotation, arguing that the Moon’s gravitational influence would gradually slow Earth’s spin and eventually lead to mutual tidal locking. This reasoning informed his broader cosmological speculation, developed the following year in the Universal Natural History and Theory of the Heavens. There he proposed a version of the nebular hypothesis, suggesting that the Solar System formed from a rotating cloud of gas. Kant also argued that the Milky Way was itself a galaxy and that distant nebulae might likewise be “island universes”, anticipating later astronomical discoveries.
Kant received his licence to lecture in 1755 and began teaching a range of subjects including mathematics, physics, logic and metaphysics. In 1756 he advanced an insight into atmospheric dynamics in his essay on the theory of winds, now recognised as an early formulation related to the Coriolis effect. That same year he wrote three studies on the devastating Lisbon earthquake of 1755, providing one of the first systematic naturalistic explanations of seismic activity. His theory, which proposed the collapse of subterranean cavities filled with gases, was incorrect but marked an important shift away from supernatural interpretations.
From 1757 Kant lectured regularly on geography, making him one of the first university lecturers to treat the subject independently. Geography became one of his most popular courses, and a compilation of his lecture material was later published in 1802 as Physical Geography. After assuming a professorship in 1770 he expanded his teaching to include natural law, ethics and anthropology.

Development of the Critical Philosophy

Kant’s early scientific and philosophical works culminated in his mature critical project. His 1770 inaugural dissertation introduced key distinctions vital to his later thought, but it was the Critique of Pure Reason that revolutionised modern philosophy. The work sought to explain the conditions under which knowledge is possible, arguing that the mind imposes conceptual structures—categories—upon the manifold of experience. Space and time, he argued, are not properties of things themselves but forms through which the sensory world is apprehended.
Kant’s second major work, the Critique of Practical Reason, presented his moral philosophy, centred on the categorical imperative and the autonomy of rational beings. His third critique, the Critique of the Power of Judgment, explored aesthetics and teleology, proposing that judgments of beauty arise from a harmonious free play of cognitive faculties.
These works together defined what later became known as transcendental idealism, a system intended to preserve empirical knowledge while validating the moral and aesthetic significance of human reason.

Legacy

Kant’s influence extends across numerous disciplines. In moral philosophy his emphasis on duty, autonomy and universal law shaped modern deontological ethics. In political theory his ideas anticipated modern concepts of international organisation and cosmopolitan citizenship. His contributions to epistemology and metaphysics set the stage for subsequent developments in German Idealism and shaped many later philosophical debates.
Kant’s later life was devoted to teaching and writing in Königsberg, where he remained until his death in 1804. While celebrated for his intellectual achievements, his legacy is tempered by his long adherence to racial theories common in his era, which he began to revise only towards the end of his life.