section_path: Biography/Early work
section_name: Early work
paragraph_text: Early work
  
  Kant is best known for his work in the philosophy of ethics and metaphysics, but he made significant contributions to other disciplines. In 1754, while contemplating on a prize question by the Berlin Academy about the problem of Earth's rotation, he argued that the Moon's gravity would slow down Earth's spin and he also put forth the argument that gravity would eventually cause the Moon's tidal locking to coincide with the Earth's rotation. The next year, he expanded this reasoning to the formation and evolution of the Solar System in his Universal Natural History and Theory of the Heavens. In 1755, Kant received a license to lecture in the University of Königsberg and began lecturing on a variety of topics including mathematics, physics, logic, and metaphysics. In his 1756 essay on the theory of winds, Kant laid out an original insight into the Coriolis force.
  
  In 1756, Kant also published three papers on the 1755 Lisbon earthquake. Kant's theory, which involved shifts in huge caverns filled with hot gases, though inaccurate, was one of the first systematic attempts to explain earthquakes in natural rather than supernatural terms. In 1757, Kant began lecturing on geography making him one of the first lecturers to explicitly teach geography as its own subject. Geography was one of Kant's most popular lecturing topics and, in 1802, a compilation by Friedrich Theodor Rink of Kant's lecturing notes, Physical Geography, was released. After Kant became a professor in 1770, he expanded the topics of his lectures to include lectures on natural law, ethics, and anthropology, along with other topics.
  
  In the Universal Natural History, Kant laid out the nebular hypothesis, in which he deduced that the Solar System had formed from a large cloud of gas, a nebula. Kant also correctly deduced that the Milky Way was a large disk of stars, which he theorized formed from a much larger spinning gas cloud. He further suggested that other distant "nebulae" might be other galaxies. These postulations opened new horizons for astronomy, for the first time extending it beyond the solar system to galactic and intergalactic realms.
  
  From then on, Kant turned increasingly to philosophical issues, although he continued to write on the sciences throughout his life. In the early 1760s, Kant produced a series of important works in philosophy. The False Subtlety of the Four Syllogistic Figures, a work in logic, was published in 1762. Two more works appeared the following year: Attempt to Introduce the Concept of Negative Magnitudes into Philosophy and The Only Possible Argument in Support of a Demonstration of the Existence of God. By 1764, Kant had become a notable popular author, and wrote Observations on the Feeling of the Beautiful and Sublime; he was second to Moses Mendelssohn in a Berlin Academy prize competition with his Inquiry Concerning the Distinctness of the Principles of Natural Theology and Morality (often referred to as "The Prize Essay"). In 1766 Kant wrote a critical piece on Emanuel Swedenborg 's Dreams of a Spirit-Seer.
  
  In 1770, Kant was appointed Full Professor of Logic and Metaphysics at the University of Königsberg. In defense of this appointment, Kant wrote his inaugural dissertation On the Form and Principles of the Sensible and the Intelligible World This work saw the emergence of several central themes of his mature work, including the distinction between the faculties of intellectual thought and sensible receptivity. To miss this distinction would mean to commit the error of subreption, and, as he says in the last chapter of the dissertation, only in avoiding this error does metaphysics flourish.
  
  It is often claimed that Kant was a late developer, that he only became an important philosopher in his mid-50's after rejecting his earlier views. While it is true that Kant wrote his greatest works relatively late in life, there is a tendency to underestimate the value of his earlier works. Recent Kant scholarship has devoted more attention to these "pre-critical" writings and has recognized a degree of continuity with his mature work.