The book presents a critical examination of the evidence for thought-transference, or telepathy, drawing upon records of the Society for Psychical Research and various independent observers. The author opens by addressing the historical neglect of psychical research and the widespread prevalence of fraud, hyperesthesia, muscle-reading, and the common mental habits that produce false resemblances in experiments. He outlines the methodological precautions necessary to exclude these sources of error in any serious scientific inquiry.
Subsequent chapters detail experiments conducted under controlled conditions to test the transference of simple sensations, such as tastes, pains, and visual images, both in the normal waking state and with hypnotised percipients. The author reviews tests involving the inhibition or origination of physical actions through silent willing, automatic writing, and table tilting. A significant portion of the work evaluates experiments in producing local anesthesia and inducing sleep or hallucinations at a distance.
Moving beyond laboratory tests, the inquiry addresses spontaneous phenomena, including coincident dreams, auditory and visual hallucinations, and collective visions. The author provides a detailed critical analysis of human testimony, highlighting the insidious effects of memory errors, confabulation, and the tendency to exaggerate coincidences. He argues that while many spontaneous cases lack rigorous proof, the aggregate body of well-attested evidence forms a consistent natural group that cannot be dismissed as mere chance.
The volume concludes with a cautious assessment of the theoretical implications of telepathy. While maintaining that the existing evidence falls short of conclusively establishing telepathy as an accepted natural law or explaining its underlying physical mechanism, the author insists that the accumulation of facts demands serious scientific attention rather than dogmatic rejection. The work serves as a foundational text in the history of psychical research, balancing a rigorous skepticism with an openness to unverified phenomena.
