Franz Anton Mesmer  (May 23, 1734 – March 5, 1815)
Franz Anton Mesmer's (born Friedrich Anton Mesmer) was born in the village of Iznang, on the shore of Lake Constance in Swabia, Germany. After studying at the Jesuit universities of Dillingen and Ingolstadt, he took up the study of medicine at the University of Vienna in 1759. In 1766 he published a doctoral dissertation with the Latin title De planetarum influxu in corpus humanum (On the Influence of the Planets on the Human Body), which discussed the influence of the Moon and the planets on the human body and on disease. This was not medical astrology—relying largely on Newton's theory of the tides, Mesmer expounded on certain tides in the human body that might be accounted for by the movements of the sun and moon.. Evidence assembled by Frank A. Pattie suggests that Mesmer plagiarized his dissertation from a work by Richard Mead, an eminent English physician and Newton's friend. That said, in Mesmer's day doctoral theses were not expected to be original.

In January 1768 Mesmer married a wealthy widow and established himself as a physician in the Austrian capital Vienna. He lived on a splendid estate and patronised the arts. In 1768, when court intrigue prevented the performance of La Finta Semplice for which a twelve-year-old Wolfgang Amadeus Mozart had composed 500 pages of music, Mesmer is said to have arranged a performance in his garden of Mozart's Bastien und Bastienne, a one-act opera, though Mozart's biographer Nissen has stated that there is no proof that this performance actually took place. Mozart later immortalized his former patron by including a comedic reference to Mesmer in his opera Cosi fan tutte.

His research into the prevalent ailment of 'hysteria' led to the theory of animal magnetism. This is comparable to modern-day stress, or in hysteria's most extreme examples, appears to bear similarity to post-traumatic stress disorder (PTSD). A contemporary of Mesmer had claimed to have discovered a physical force in all living things (people, trees, plants and animals) through which humans would reach the hysteria state instantly on contact with a specially "magnetised" tree or bush. Following an elaborate ceremony 'magnetizing' trees, sufferers of hysteria or hysterical nature would touch the tree and experience something akin to a fit, after which the hysteria would usually not recur.

Mesmer staged an animal magnetism without having 'magnetized' the trees to illustrate that the ceremony was a sham. However, all of the volunteers for Mesmer's event had the same effect from the non-prepared trees. That is, the very suggestion of animal magnetism being at work was enough to create the bodily response.

Mesmer then wrote various theses on this previously unheard-of psychological effect, later termed [mermerism] as shorthand for the effect. In common parlance, we have since re-termed this the Placebo Effect.