lectures at the University of Göttingen. He adopted Buffon's theory of degeneration in his dissertation De Generis Humani Varietate Nativa. The central premise of this work was that all of mankind belonged to the same species. Blumenbach believed that a multitude of factors, including climate, air, and the strength of the sun, promoted degeneration and resulted in external differences between human beings. However, he also asserted that these changes could easily be undone and, thus, did not constitute the basis for speciation. In the essay “Über Menschen-Rassen und Schweine-Rassen,” Blumenbach clarified his understanding of the relationship between different human races by calling upon the example of the pig. He contended that, if the domestic pig and the wild boar were seen as belonging to the same species, then different humans, regardless of skin color or height, must too belong to the same species. For Blumenbach, all people of the world existed as different gradations on a spectrum. Nevertheless, the third edition of De Generis Humani Varietate Nativa, published in 1795, is famed among scholars for its introduction of a system of racial classification which divided humans into members of the Caucasian, Ethiopian, Mongolian, Malayan, or American races. Blumenbach's views on degeneration emerged in dialogue with the works of other thinkers concerned with race and origin in the late eighteenth century. In particular, Blumenbach participated in fruitful intellectual exchange with another prominent German scholar of his age, Immanuel Kant. Kant, a philosopher and professor at the University of Königsberg, taught a course on physical geography for some forty years, fostering an interest in biology and taxonomy. Like Blumenbach, Kant engaged closely with the writings of Buffon while developing his position on these subjects. In his 1777 essay “Von der verschiedenen Racen der Menschen,” Kant expressed the belief that all humans shared a common origin. He called upon the ability of humans to interbreed as evidence for this assertion. Additionally, Kant introduced the term “degeneration,” which he defined as hereditary differences between groups with a shared root. Kant also arrived at a meaning of “race” from this definition of degeneration. He claimed that races developed when degenerations were preserved over a long period of time. A group could only constitute a race if breeding with a different degeneration resulted in “intermediate offspring." Although Kant advocated for a theory of shared human origin, he also contended that there was an innate hierarchy between