Rivers lifted his hands to his chin, smelling the medical school smell of human fat and formaldehyde, only partially masked by carbolic soap. He watched Head’s expression as he looked at Lucas’s shaved scalp, and realized it differed hardly at all from his expression that morning as he’d bent over the cadaver. For the moment, Lucas had become simply a technical problem. Then Lucas looked up from his task, and instantly Head’s face flashed open in his transforming smile. A murmur of encouragement, and Lucas returned to his drawing. Head’s face, looking at the ridged purple scar on the shaved head, again became remote, withdrawn. His empathy, his strong sense of the humanity he shared with his patients, was again suspended. A necessary suspension, without which the practice of medical research, and indeed of medicine itself, would hardly be possible, but none the less identifiably the same suspension the soldier must achieve in order to kill. The end was different, but the psychological mechanism employed to achieve it was essentially the same. What Head was doing, Rivers thought, was in some ways a benign, epicritic form of the morbid dissociation that had begun to afflict Prior. Head’s dissociation was healthy because the researcher and the physician each had instant access to the experience of the other, and both had access to Head’s experience in all other areas of his life. Prior’s was pathological because areas of his conscious experience had become inaccessible to memory. What was interesting was why Head’s dissociation didn’t lead to the kind of split thta had taken place in Prior. Rivers shifted his position, and sighed. One began by finding mental illness mystifying, and ended by being still more mystified by health.

—The Eye in the Door