The most significant theme in this novel is the conflict between freedom and control, expressed as the conflict between Erudite’s attempt to exert control over the minds and behavior of the population versus the Divergent mentality that seeks freedom and choice outside the boundaries of the factions.

The Erudite, as represented by Jeanine Matthews, are the antagonists of this novel. Jeanine’s evil plan includes controlling the Divergent in order to consolidate Erudite power within the faction system. The loyal Dauntless seek the destruction of the Erudite at all costs; they are determined to maintain their freedom and to get revenge for being used as Erudite’s soldier-pawns in the eradication of the Abnegation. 

However, Tris sees that the Erudite hold technology and knowledge that their society requires to function. All the Erudite’s knowledge cannot be destroyed; in fact, some of it must be preserved for everyone to survive. For example, the Erudite now hold the stolen information that Tris’s parents died trying to preserve: what lies beyond the walls of the factions, outside the perimeter fence guarded by the Dauntless? 

Implicitly, the message is that a government needs to control both the information available to its citizens and their behavior in order to remain in power.