Freud and Ben Franklin were among the pioneers of bilateral therapy.

"It still strikes me as strange that the case histories I write should read like short stories and that, as one might say, they lack the serious stamp of science."

- Sigmund Freud, 1895

The first person to develop a system that involved bilateral cross-hemispheric stimulation was a man named Franz Anton Mesmer. In the late 1700s, Mesmer, an Austrian physician who lived in France, healed people of trauma by a variety of techniques that he believed stimulated people's "animal magnetism," which he defined as the animating life force within the human body. To accomplish this healing he sometimes used lodestones (magnets) or water that he had "magnetized." He even claimed to use the direct force of his own "magnetism," including a technique of holding two fingers in front of a patient's face and gently waving the fingers from side to side for a few minutes at a time while the patient held her or his head steady and followed the physician's fingers with the eyes. As Mesmer's biographer James Wyckoff wrote, "Mesmer now considered passes with his hand as the essential part of his cure."

This pioneering physician termed his system mesmerism, and for the latter part of the eighteenth century he was one of the most famous and notorious physicians in Europe. Wolfgang Amadeus Mozart was a friend of Mesmer, and his opera Bastien et Bastienne was performed in 1768 in the garden of Mesmer's home. Mozart later wrote Mesmer into his opera Così fan tutte:

This magnetic stone
Should give the traveler pause.
Once it was used by Mesmer,
Who was born
In Germany's green fields,
And who won great fame
In France.

Mesmer's system was often highly effective and was widely practiced to treat all manner of physical and psychological ailments, although he was careful not to take patients suffering from clearly "organic" problems such as cancers, sexually transmitted diseases, and other types of obvious infections. Trained as a classical physician, by making this distinction Mesmer was separating out those to whom he either would prescribe medications or would refer to other physicians for surgery or other medical techniques.

Mesmer's special interest was in those conditions caused by a lack of vitality, or magnetism - what Freud referred to as hysteria and what today would be considered psychosomatic or psychiatric conditions - those caused by or rooted in emotional trauma. At the height of his career, Mesmer trained hundreds of physicians across Europe in his techniques and had a following that included royalty and people from the highest echelons of society, as well as the most destitute, whom he treated for free.

As happens with many new and unconventional therapies, the medical establishment of his day decided that Mesmer was a threat to them.

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