When Oliver Sacks was a medical student, he met with a patient who described going to the hospital for some tests—neurologists told him that he had a “lazy” left leg. The next morning, the patient woke up and, according to him, found a severed leg in his bed. Assuming that the doctors were playing a nasty prank on him, the patient tried to throw the leg out of the bed—only to fall out of bed and realize that the leg was attached to his body. Revolted, the patient tried to tear his leg off. When Oliver Sacks met with the patient, he asked, “Don’t you know your own leg?” The patient insisted that his leg wasn’t his real leg. Sacks asked the patient where his “real” left leg was. Distressed, the patient admitted he didn’t know.
The patient in this chapter feels a sense of disembodiment similar to that of Christina in the previous chapter—the difference being that this patient feels disembodied from his leg, rather than his entire body. Notice that Sacks doesn’t actively disagree with the patient during his interview; he just tries to use logic and reason to persuade the patient to see the plain truth—that is his leg after all.
In the Postscript, Sacks mentions a similar case, in which a patient with a left hemiplegia (paralysis of one side of the body) reported waking up with a disembodied leg in his bed, and then falling out of bed when he realized the leg was attached to his body.
This is one of the shortest chapters in the book, and one of the few in which Sacks doesn’t write about his patient’s attempts to cope with their neurological disorder. As usual, Sacks uses the Postscript to clarify medical issues and compare different patients’ conditions.