No doubt a great importance in the paranormal field is the problem of fraud. The field of psychic research and spiritualism has been so notoriously full of charlatans, such as the Fox sisters and Eusapia Palladino–individuals who claim to have special power and gifts but who are actually conjurers who have hoodwinked scientists and the public as well–that we have to be especially cautious about claims made on their behalf.
Some scientists of the period who investigated spiritualism also became converts. They included chemist Robert Hare, physicist William Crookes (1832–1919) and evolutionary biologist Alfred Russel Wallace (1823–1913). Nobel laureate Pierre Curie took a very serious scientific interest in the work of medium Eusapia Palladino. Other prominent adherents included journalist and pacifist William T. Stead (1849–1912) and physician and author Arthur Conan Doyle (1859–1930).