Galton's definition of hallucinations and illusions

   In 1883 the British scientist Sir Francis Galton (1822-1911) defined hallucinations and illusions as follows: "Hallucinations are defined as appearances wholly due to fancy; illusions, as fanciful perceptions of objects actually seen."

   References

   Galton, F. (1883). Inquiries into human faculty and its development. London: J.M. Dent & Sons.