Joseph Delboeuf
[1] He published works across a diverse range of subjects including the curative effects of hypnotism.
[5][2] He received a scholarship from the University of Bonn and continued his postdoctoral research under philosopher and mathematician Friedrich Ueberweg.
[4] In 1860, he began teaching Greek at l’Ecole Normale des Humanités de Liège.
[4] In 1863, he was given the post of Maitre de Conférences, which he only held for a few months before being appointed Chair of Philosophy at University of Ghent, leaving his research in mathematics.
[5][4] There, he met Joseph Plateau, who helped him publish his first two notes on optical illusions in the Bulletin of the Royal Academy of Belgium.
After completing work on sleep and dreams, Delboeuf started researching magnetism and hypnotism.
[7] At the First International Congress on scientific and experimental hypnotism (1889), a motion was put forward to ban non-medical practitioners from using hypnosis.
[8] However, Delboeuf argued that a medical degree was not required to practice hypnotism; rather, it should be used freely, yet with caution.
[8] Along with a group of magnetizers in Verviers, he argued that hypnotists had specific personal skills that could not be acquired by all doctors.
[9] He would make two identical lesions on two parts of the body (e.g., arms) and would apply hypnotism to one area while leaving the other alone for nature to act upon.
They highlighted that subjects are unable to remember the suggestion when they wake because the memory is only available in the dream-like or hypnotic state.
He tested his predictions in an experiment with Marie Wittman, who was awakened in the middle of a hypnotic hallucination and remembered everything.
[3] During his time at the University of Bonn, Delboeuf published Prolégomènes philosophiques à la géométrie (1860), disputing his mentor Ueberweg’s concept of Euclidean space and earning the praise of Bertrand Russell.
[13] Delboeuf proposed that, because a negative value of S did not make sense, the formula could not be applicable to all cases.
[13] For example, in cases where the strength of a sensation may lead to inability to view an external stimulus (for instance due to glare), the formula would not be applicable.
[13] This supplementary equation would account for the change that a sense organ experiences due to the magnitude of excitation from an external stimulus.
[13] By adding this equation, Delboeuf accounted for fatiguing effects that sensations have on sense organs.
[13] Delboeuf investigated the laws of nature and sensation in his paper "General Theory of Sensitivity.
[15] Delboeuf started researching perception after meeting Joseph Plateau (1801-1883), a physicist known for his work on vision.
