Koch's postulates were derived from Robert Koch's work on infectious diseases, such as anthrax and tuberculosis, which still engage us to this day. These guidelines were an attempt to establish a standard for identifying the specific causation of an infectious disease and to convince sceptics that microorganisms could cause disease. They were also established to encourage an increasing number of novice microbiologists to use more rigorous criteria before claiming a causal relationship between a microorganism and a disease.