In later life, the creator of Sherlock Holmes became an evangelist for spiritualism. 

German biologist and philosopher (1867-1941) who published extensively on psychical research, considering it to be empirical support for his theory of vitalism.

German philosopher (1839-1899), a prominent theoretician and proponent of research into postmortem survival, psychic phenomena and the unconscious mind. 

 American philosopher who in 1961 published a major study of psi phenomena, endorsing their existence and arguing that they constitute evidence for postmortem survival. This article describes and critiques his ideas. 

Manager of the Princeton Engineering Anomalies Research (PEAR) laboratory (1944–2022), whose remote viewing and psychokinesis research made important contributions to parapsychology.

Ramses D’Leon Macias, a graduate student at Mexico’s Universidad UTEL, has carried out psi research in presentiment and psychokinesis.

 Professor of philosophy at Rollins College, Orlando, Florida, who has carried out psi research, principally in the area of psychokinesis.

American lawyer, judge, and politician (1799-1874), remembered as one of the first serious investigators of séance mediums.

American psychoanalyst and paranormal investigator (1908-1998) known for his three-year study of  the ‘thoughtography’ practised by Ted Serios, and for his insightful theorising about the role of unconscious motivation in the manifestation of psi effects.

Italian scientist (1858-1898) who showed early brilliance in research into electricity but devoted most of his time to telepathy and other psychical phenomena before his untimely death aged 39.