| Quote #1
Then hurriedly he begged her to forgive him; he felt he should have looked after her better, he’d been most remiss. (1.2.21)
Rieux is Mr. Responsible when it comes to the citizens of Oran, but he neglects his wife in order to do so. This looks like a classic case of abstraction – he chooses the idea of duty (for the good of society) over the concrete case of duty (for the good of the individual) staring him in the face.
| Quote #2
He merely replied, without looking at the police officer, that "a secret grief" described it well enough. The inspector then asked him peremptorily if he intended to "have another go at it." Showing more animation, Cottard said certainly not, his one wish was to be left in peace. (1.4.30)
Cottard has skipped out on his duty as a citizen and become a criminal; this makes him an exile in the normal world but a free man during the plague.
| Quote #3
If, as was most likely, it died out, all would be well. If not, one would know […] what steps should be taken for coping with and finally overcoming it.
Rieux states that the way to combat the plague is very clear: you just have to do your job. But is he referring to his job as a doctor, or as a citizen? Does Rieux fight the plague as a medical professional, or as a merely decent man?