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 existing races. In 1788, Kant wrote “Über den Gebrauch teleologischer Prinzipien.” He maintained in this work that a human's place in nature was determined by the amount of sweat the individual produced, which revealed an innate ability to survive. Sweat emerged from the skin. Therefore, skin color indicated important distinctions between humans.