Quotable Quotes

“I have a theory that selflessness and bravery aren't all that different.”
-Tris

This is one of the first character-defining moments for Tris early in the book.  Up until this point, having lived as Abnegation, being selfless, self-forgetting, and "Stiff", she thought she could never live up to the ideals of Dauntless, particularly as she lives as a Divergent.  She thought she was an outsider more than ever, fitting in nowhere, a jack of all trades, master of none.  But here, she finally sees clearly.  She finally understands what nobody else does; that being selfless and being brave, in fact all five of the traits, are not mutually exclusive.  And then she kicks it into overdrive.

“I feel like someone breathed new air into my lungs. I am not Abnegation. I am not Dauntless. 
I am Divergent.” 
-Tris

Another characterization moment for Tris.  She has realized something deeply personal about herself.  She has realized that she is not a single thing.  She does not just possess bravery, nor just selflessness.  She is in command of her actions, and refuses to fit into a neat little box.  She is Divergent.  She is her own person.

"It’s when you’re acting selflessly that you are at your bravest."

-Four

This can speak pretty deeply to anybody reading.  It is deeply significant to the fact that the virtues of the factions are not mutually exclusive.  When any of the characters rebelled, they could have easily been thinking of themselves, and nobody else.  But...they weren't.  Tris is the biggest example of this.  She subconsciously does things without caring for herself.  The Dauntless, contrariwise, need someone else to do things for them, and continually turn to her, in growing amounts, as the plot progresses.   This allows her to grow, and develop as a person, and take on leadership roles she had never imagined for herself.  The support of those behind her only serves to further her courage and bravery.

“Human reason can excuse any evil; that is why it's so important that we don't rely on it.” 

-Tris, quoting her father Andrew Prior

This is a quote central to the underlying conflict present in the structure of the faction system.  Because conflict arose when people thought however they pleased, it was decided to shove everyone into five neat packages.  If anyone diverged from this pattern of organized thought, they were viewed as something to be feared and exterminated.  This was simultaneously an example of human reason excusing the evil of killing others, and an example of them throwing human reason out the window to establish this mode of thought.  Andrew Prior likely knew of this all, for his own, unique reasons, and was subtly hinting at it to his daughter.