Adrien Sixte (ah-DRYEHN seekst), a brilliant philosopher, teacher, and writer who develops a deterministic theory that each effect comes from a cause, and that if all causes are known, results can be predicted accurately in all forms of human activity. The strict regularity of his life is interrupted by Robert’s arrest, and his reading of Robert’s confessional manuscript makes him feel morally responsible for Robert’s acts. Again, at Robert’s funeral, Adrien feels a moral guilt in the death of his disciple.
Robert Greslou (grehs-LEW), his disciple, a precocious student of philosophy who tests his master’s theory by seducing Charlotte after providing causes that produce the result he wishes to achieve. Pretending to enter a suicide pact, he spends a night with her, then repudiates the pact and leaves. Arrested on suspicion of murder, he is willing to die to keep Charlotte’s suicide a secret, but he is acquitted after André’s testimony. As they reach the street after the trial, André shoots Robert in the head.
M. de Jussat
M. de Jussat (zhew-SAH), a hypochondriac and a boorish nobleman.
Charlotte, his beautiful young daughter who, suffering from discovery of Robert’s duplicity, drinks strychnine after writing a suicide note to André.
André, her older brother, an army officer fond of hunting and riding. Influenced by Adrien to free Robert from the murder charge, he then avenges his sister’s seduction and death.
Lucien (lew-SYAHN), Charlotte’s younger brother, a fat, simple boy of thirteen who is tutored by Robert.