Dr. Richard is clearly trying to be the voice of reason when the plague outbreak begins. While Rieux is quick to recommend preventative action like quarantine and serum, Richard is all, "Wait just a second here folks." Until they know that it’s the plague, he argues, they shouldn’t act as though it’s the plague.
Like Grand, Richard in his obsession with terminology shows how language gets in the way of action. "Are you absolutely convinced it’s the plague?" he asks of Rieux, who replies, "You’re stating the problem wrong."
Richard would also remind us of the uselessness of optimism. He is optimistic that the plague isn’t actually the plague, that his patients are momentarily getting better, and that when the pestilence is at its worst, at least it can only get better! Then he dies. Of the plague. This is one in a series of "responses" given by the world to statements like this very one of Dr. Richard’s. (Others include the wind rushing through the doors at a key moment in Paneloux’s sermon and Jacques’s wail as response to Paneloux’s plea for God's mercy.)
So Dr. Richard suffers tragically while Camus makes his point that the world is cruel and indifferent. That’s it in a nutshell.