Final answer:
Jean-Martin Charcot had two main theories: one detailing the pathology of neurological diseases and another involving the use of hypnosis in treating hysteria, which influenced modern neurology and psychiatry respectively.
Step-by-step explanation:
The two theories of Charcot that are widely recognized are his work on neurology and hypnotism. Jean-Martin Charcot was a pioneering French neurologist whose work significantly contributed to the understanding of neurological disorders. His first theory involved the pathology of neurological diseases, where he cataloged symptoms, traced back their origins to specific locations in the nervous system, and laid the groundwork for modern neurology. His second theory is the use of hypnosis in the treatment of what was then known as hysteria, leading to the development of dynamic psychiatry and eventually influencing the work of Sigmund Freud.