Why is it necessary to question Dr. Rieux's claims of objectivity in his chronicle?

Despite Dr. Rieux's claims of objectivity, his description of pre-plague Oran is heavily laced with irony. Rieux states that the spirit of pre-plague Oran is one of empty commercialism. The lives of Oran's people, he affirms, are entirely circumscribed by their habits: every day, they follow the same routines of work, movies, cafes, and shallow love affairs. Rieux implies that the people of Oran are enslaved to their habits when he observes that Tarrou is not enslaved by his habits.

Tarrou's notebooks contain a philosophical examination of how not to "waste time." What is ironic about the methods he suggests to avoid wasting time??

Tarrou posits that one does not waste time only when one is always aware of time. He muses that one can make oneself aware of time by indulging in intricate, frustrating, complicated routines. However, his ideas are too abstract to really address the larger issue of how not to waste one's life. Moreover, his suggestions are far too similar to habitual routines to really make productive use of time. He defines the productive use of time in terms of filling it with frustrating, tedious activities instead of the pleasurable ones that Oran's people use to fill their time. Simply being aware of time via constant frustration does not necessarily mean that one is not wasting time.

At one point, Rambert accuses Rieux of using the language of abstraction rather than the language of the heart. What is the significance of his accusation?

Rambert accuses Rieux of being abstract because Rieux refuses to aid him in his attempts to escape Oran by giving him a certificate that declares him plague- free. Rambert comes very close to accusing Rieux of indifference. Rieux disagrees: he does admit that he hardens his heart against the suffering of individual people, but denies that he is indifferent to their suffering. Indifference is a state of inaction or denial in response to other people's suffering. It is only through hardening his heart, Rieux believes, that he will be able to bear the suffering enough to allow him to try to fight the plague as best he can.