The central conflict of The Giver is Jonas versus his society. Although he accepts his society's rules without question early in the novel, through his work with the Giver, Jonas realizes that the decisions made for citizens are not as fair as they are created to be. In chapter 19, when he learns that his father kills newborns, putting young Gabriel in danger of actual death, it is almost too much for Jonas to bear. He realizes that he and the Giver are the only ones who experience true feelings because they are the only ones who share the memories of the past. This is pivotal in Jonas's decision to try to create a new future for the people of their world.
The decision to leave, allowing the memories to be returned to their community, creates a conflict of Jonas versus himself. In chapter 20, he doubts himself and wants the Giver to come with him. The Giver reminds him that the people will need someone to guide them through the pain of feelings they have never had to process. Jonas begs the Giver to come with him but comes to accept that the Giver needs to remain behind in order for their plans to work and in order to create the new world they desire.
Because of his growing sense of knowledge, Jonas sometimes experiences conflict with others that they don't even know about. For example, in chapter 17, when Jonas learns about war and death, he suddenly sees their recreational shooting games in a new way, and Asher doesn't understand his friend's refusal to play:
"You ruined it," Asher said in an irritated voice.
"Don't play it anymore," Jonas pleaded.
"I'm the one who's training for Assistant Recreation Director," Asher pointed out angrily. "Games aren't your area of expertness."
"Expertise," Jonas corrected him automatically.
"Whatever. You can't say what we play, even if you are going to be the new Receiver." Asher looked warily at him. "I apologize for not paying you the respect you deserve," he mumbled.
"Asher," Jonas said. He was trying to speak carefully, and with kindness, to say exactly what he wanted to say. "You had no way of knowing this. I didn't know it myself until recently. But it's a cruel game. In the past, there have—"
"I said I apologize, Jonas."
As Jonas continues to receive memories, he finds that the people around him increasingly generate feelings of conflict, yet they can't be held responsible because they simply have no knowledge base from which to make decisions.