Maudsley was agnostic, and as such critical of religion and reports of ostensibly supernatural phenomena. In his book Natural Causes and Supernatural Seemings (1886) he wrote that so-called supernatural experiences were disorders of the mind and simply "malobservations and misinterpretations of nature".Ivan Leudar, Philip Thomas. (2000). Voices of Reason, Voices of Insanity: Studies of Verbal Hallucinations. Routledge. pp. 106–107. His book is seen as an early text in the field of anomalistic psychology.
