Building upon the idea that a specific disease is caused by a specific microbe, Robert Koch proposed a series of postulates. Using these postulates, Koch and his colleagues were able to definitively identify the causative pathogens of diseases such as anthrax, tuberculosis, and cholera. Koch's 'one microbe, one disease' concept represented the culmination of the ${}19$th century's paradigm shift away from the miasma theory and toward the germ theory of disease.