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. History The concept of degeneration arose during the European enlightenment and the industrial revolution – a period of profound social change and a rapidly shifting sense of personal identity. Several influences were involved. The first related to the extreme demographic upheavals, including urbanization, in the early years of the 19th century. The disturbing experience of social change and urban crowds, largely unknown in the agrarian 18th century, was recorded in the journalism of William Cobbett, the novels of Charles Dickens and in the paintings of J M W Turner. These changes were also explored by early writers on social psychology, including Gustav Le Bon and Georg Simmel. The psychological impact of industrialisation is comprehensively described in Humphrey Jennings' masterly anthology Pandaemonium 1660 - 1886. Victorian social reformers including Edwin Chadwick, Henry Mayhew and Charles Booth voiced concerns about the "decline" of public health in the urban life of the British working class, arguing for improved housing and sanitation, access to parks and recreational facilities, an improved diet and a reduction in alcohol intake. These contributions from the public health perspective were discussed by the Scottish physician Sir James Cantlie in his influential 1885 lecture Degeneration Amongst Londoners. The novel experience of everyday contact with the urban working classes gave rise to a kind of horrified fascination with their perceived reproductive energies which appeared to threaten middle-class culture. Secondly, the proto-evolutionary biology and transformatist speculations of Jean-Baptiste Lamarck and other natural historians—taken together with the Baron von Cuvier's theory of extinctions—played an important part in establishing a sense of the unsettled aspects of the natural world. The polygenic theories of multiple human origins, supported by Robert Knox in his book The Races of Men, were firmly rejected by Charles Darwin who, following James Cowles Prichard, generally agreed on a single African origin for the entire human species. Thirdly, the development of world trade and colonialism, the early European experience of globalization, resulted in an awareness of the varieties of cultural expression and the vulnerabilities of Western civilization. Finally, the growth of historical scholarship in the 18th century, exemplified by