How we cite our quotes:
"What do you mean by ‘common decency’?" Rambert’s tone was grave.
"I don’t know what it means for other people. But in my case I know that it consists in doing my job."
"Your job! I only wish I were sure what my job is!" There was a mordant edge to Rambert’s voice. "Maybe I’m all wrong in putting love first."
Rieux looked him in the eyes.
"No," he said vehemently, "you are not wrong." (2.9.242-6)
Here’s an idea for you: Rieux is jealous of Rambert. In fact, Rieux isn’t a selfless healer at all – he’s just trying to avoid having to take care of his wife. Tending victims of the plague is his excuse for not tending the woman who needs him most. He envies Rambert’s conviction and the strength of his love for his "wife" in Paris. Do you agree?
"I suppose you don’t know that Rieux’s wife is in a sanatorium, a hundred miles or so away."
Rambert showed surprise and began to say something; but Tarrou had already left the room.
At a very early hour the next day Rambert rang up the doctor.
"Would you agree to my working with you until I find some way of getting out of town?"
There was a moment’s silence before the reply came.
"Certainly, Rambert. Thanks." (2.9.253-8)
Faced with the example set by others, Rambert realizes his duty is in fact to the town. Of course, he’s still going to leave town ASAP, but it’s a step in the right direction. Rieux, being himself, doesn’t judge Rambert, either, for any of his decisions.
"Then why don’t you stop my going? You could easily manage it."
Rieux shook his head […]. It was none of his business, he said. Rambert had elected for happiness, and he, Rieux, had no argument to put up against him. Personally he felt incapable of deciding which was the right course and which the wrong in such a case as Rambert’s.
"Perhaps […] I, too, would like to do my bit for happiness." (4.2.10-14)
More evidence for our Rieux-doesn’t-want-to-take-care-of-his-wife theory. Not only is he complicit in Rambert’s illegal escape by his silence, but now he’s actively helping the man by alerting him to growing suspicions. Because Rieux can’t do for his own wife what Rambert is doing for his, he seeks love and happiness in this vicarious manner.