Hallucinations

Charles Bonnet was an eighteenth-century Swiss naturalist whose investigations ranged broadly, from entomology to reproduction and regeneration in polyps and other animalcules. When an eye disease made his beloved microscopy impossible, he turned to botany — he did pioneer experiments on photosynthesis — then to psychology, and finally to philosophy. When he heard that his grandfather Charles Lullin had started to have “visions” as his eyesight failed, Bonnet asked him to dictate a full account.

John Locke, in his 1690 Essay Concerning Human Understanding, put forward the notion that the mind is a tabula rasa until it receives information from the senses. This “sensationalism,” as it was called, was very popular with the philosophes and rationalists of the eighteenth century, including Bonnet. Bonnet also conceived of the brain as “an organ of intricate composition, or rather an assemblage of different organs.” These different “organs” all had their own dedicated functions. (Such a modular view of the brain was radical at the time, for the brain was still widely regarded as undifferentiated, uniform in structure and function.) Thus Bonnet attributed his grandfather’s hallucinations to continuing activity in what he postulated were visual parts of the brain — an activity drawing on memory now that it could no longer draw on sensation.

Bonnet — who would later experience similar hallucinations when his own eyesight declined — published a brief account of Lullin’s experiences in his 1760 Essai analytique sur les facultés de l’âme, a book devoted to considering the physiological basis of various senses and mental states, but Lullin’s original account, which filled eighteen pages of a notebook, was subsequently lost for nearly 150 years, coming to light only at the beginning of the twentieth century. Douwe Draaisma has recently translated Lullin’s account, including it in a detailed history of Charles Bonnet syndrome in his book Disturbances of the Mind.¹

Unlike Rosalie, Lullin still had some eyesight left, and his hallucinations were superimposed on what he saw in the real world. Draaisma summarized Lullin’s account:

In February 1758, strange objects had begun to float into his field of vision. It started with something that resembled a blue handkerchief, with a small yellow circle in each corner.… The handkerchief followed the movement of his eyes: whether he was looking at a wall, his bed, or a tapestry, the handkerchief blocked out all the ordinary objects in his room. Lullin was perfectly lucid and at no time did he believe that there really was a blue handkerchief floating around.…

One day in August two granddaughters came to see him. Lullin was sitting in his armchair opposite the mantelpiece, and his visitors were to his right. From the left, two young men appeared. They were wearing magnificent cloaks, red and grey, and their hats were trimmed with silver. “What handsome gentlemen you’ve brought with you! Why didn’t you tell me they were coming?” But the young ladies swore that they saw no one. Like the handkerchief, the images of the two men dissolved within a few moments. They were followed by many more imaginary visitors in the next few weeks, all of them women; they were beautifully coifed and several of them had a small box on their head.…

Somewhat later Lullin was standing at the window when he saw a carriage approaching. It came to a halt at his neighbour’s house and, as he watched in amazement, the carriage grew bigger and bigger until it was level with the eaves of the house some thirty feet from the ground, with everything perfectly in proportion.… Lullin was amazed by the variety of images he saw: one time it was a swarm of specks that suddenly turned into a flight of pigeons, another time a group of dancing butterflies. Once he saw a rotating wheel floating in the air, the kind you saw in dockside cranes. On a stroll through the town he stopped to admire an enormous scaffolding, and when he arrived home he saw the same scaffolding standing in the living room, but then in miniature, less than a foot high.

As Lullin found, the hallucinations of CBS would come and go; his lasted for some months and then disappeared for good.