The horse’s bit is a minor symbol of control, arising briefly at the end of the story. Rivers dreams he that he is trying to force a horse’s bit into a patient’s mouth, just as Yealland forced the electrode into Callan’s mouth. For Rivers, his wielding of the bit as a means of control over a patient reflects his own lurking guilt and fear that through his psychiatry, he exerts undue control over his own patients, repairing their minds and sending them back to combat when their minds had triggered their mental breakdowns precisely to remove themselves from combat.
The Horse’s Bit Quotes in Regeneration
Just as Yealland silenced the unconscious protest of his patients by removing the paralysis, the deafness, the blindness, the muteness that stood between them and the war, so, in an infinitely more gentle way, [Rivers] silenced his patients, for the stammerings, the nightmares, the tremors, the memory lapses of officers were just as much unwitting protests as the grosser maladies of men.