An Essay Towards a Theory of Apparitions

An Essay Towards a Theory of Apparitions, published in 1813 by John Ferriar, is a scientific exploration of the phenomenon of apparitions. Ferriar systematically examines historical anecdotes and personal testimonies, proposing medical and psychological explanations for these spectral impressions. He investigates the human sensory system and how physiological states influence perceptions, ultimately arguing that many apparitions can be attributed to illusions and delusions rather than supernatural causes.