Alphonso Daudet suffered from a form of syphilis that caused his back to waste away. (What's with writers and venereal disease? Maupassant had syphilis. Tolstoy was treated for venereal disease when he was 22. Hasty Generalization?)
Julian Barnes writes:
His response, both personal and literary, to his condition was admirable. "Courage... means not scaring others," Larkin wrote. Numerous witnesses attest to Daudet's exemplary behaviour. His last secretary, André Ebner, remembered Daudet sitting with a friend one morning, eyes closed, barely able to speak, martyred by pain. The door-knob gently turned, but before Mme Daudet could enter, her husband was on his feet, the colour back in his cheeks, laughter in his eye, his voice filled with reassurance about his condition. When the door closed again Daudet collapsed back into his chair. "Suffering is nothing," he murmured. "It's all a matter of preventing those you love from suffering."