IN 1628, a young woman in the town of Dole, in what is now eastern France, believed she was visited by a ghost. The young woman was ill in bed. At first she saw an ordinary woman who had tidied up and taken care of her. She began to think that her nurse might be a spirit after the kind woman appeared at her side without opening the locked door. The spirit, she believed, was the ghost of her aunt, who came to help her out as a form of penance to lessen the aunt’s time in purgatory.

We think of ghosts as wispy and translucent — a vaporous woman, perhaps, who floats down the stairs, her dress trailing in the languid air behind her. But in early modern Europe, ghosts were often perceived as solid persons. The viewer discovered that they weren’t when they did something that ordinary humans could not, like bypassing a locked door to enter a room.

By the 19th century, people had begun to think of ghosts predominantly as spectral forms — ephemeral, elusive, evanescent. When the ghost of Marley appeared to Scrooge in Dickens’s “A Christmas Carol” (1843), and Scrooge looked his transparent body “through and through,” he illustrated a shift in the ways ghosts became real to people, how ghosts were seen and remembered.

In “Spectres of the Self,” the cultural historian Shane McCorristine points to two reasons for this transmutation. The first was skepticism about the supernatural, generated by the new developments in science. The concept of hallucination emerged to explain experiences like seeing an apparition. As the seeing of ghosts became a psychological phenomenon, it also became a pathological one. In 1848, the British skeptic Charles Ollier spoke for many when he wrote that “anyone who thinks he has seen a ghost, may take the vision as a symptom that his bodily health is deranged.” As a result, Dr. McCorristine writes, the ghost was gradually relocated “from the external, objective and theological structured world to the internal, subjective and psychological haunted world of personal experience.”