When the chapter opens, Rieux is at home waiting for Tarrou to show up (for a meeting Tarrou requested) and looking at his mother.
Mme. Rieux is sitting with her hands folded in her lap; something she does quite frequently, we’re told.
We find out that the death tolls are rising and that the anti-plague serum from Paris seems to be ineffective.
Rieux’s mother says she isn’t afraid. In old age, she argues, there is little to fear.
Tarrou shows up. He thinks the government is doing a bad job responding to the plague.
He argues that what they really need is imagination. (Doesn’t this sound familiar? Yes, it does – check out the very end of Part I, when Rieux says essentially the same thing.)
Tarrou reveals a (presumably imaginative) plan he’s drawn up for getting voluntary helpers to combat the plague.
Rieux thinks this is all well and good, but has Tarrou considered the fact that volunteers are likely to DIE from the PLAGUE?
Tarrou responds by asking if Rieux heard Paneloux’s sermon.
This begins a weighty philosophical discussion. Rieux argues that he doesn’t believe in God and that the priests who have seen death up close and personal know they can’t really discuss "truth […] with a capital T." He says they need to relieve human suffering before talking about its excellence. (In other words, you can preach until the cows come home about how suffering is God’s punishment, and about how it’s going to help you better yourself, but if people are still dying, then you’re pretty useless with all your chit-chat.)
Tarrou wants to know how Rieux can be so devoted (to helping humanity, we think) if he doesn’t believe in God. Tarrou wants to be able to answer this question for himself.
Rieux says he wants to help not in spite of, but because he doesn’t believe in God. If there were a God, then God would heal the sick; Rieux wouldn’t have to. Since there isn’t a God, he has to do what he can.
Rieux suddenly feels he wants to unburden himself to this man; he feels they share a kinship. So he says he entered the medical profession as a mere career, but that watching people die – especially those who refuse to die – has changed him.
Now he believes we should all struggle against death, even knowing that death is inevitable.
Tarrou asks who taught him all this, and Rieux replies, "Suffering."
When Tarrou decides that the doctor is "perfectly right," Rieux asks him what he knows about it.
Tarrou responds that he has "little left to learn." He affirms that he does, in fact, know everything there is to know about life.
Still defending his "let’s get some volunteers!" plan, Tarrou narrates that 100 years ago a plague wiped out an entire population in Persia, except for one man whose job it was to wash the dead bodies (which you’d think would be a right quick path to disease).
Tarrou adds that the reason he’s doing this is because of his code of morals, which he identifies to be "comprehension."