Barring the first couple of pages I read this from start to finish in one session. It was that compelling. There were a few short pauses when I was worried about slushy romantic moments but I needn't have worried.
The heroine was strong, brave and despite what she first thought, selfless. She is by no means perfect, she grows and struggles with her nature and identity throughout as she learns to face both her own and other people's fears.
Ultimately this book can be summed up by the following quote by Tris's mother:
"Human beings as a whole cannot be good for long before the bad creeps back in and poisons us."
This is a truth that is expertly portrayed by the author. We're a flawed race. We will always want something more. Greed, jealousy, ambition, power -we always want what we don't have, or as Tris muses at one point, those in power and value it above all else will, in order to keep it, hand power to those that don't want it, to protect their own positions and aspirations.
Great book. I highly recommend it.
P.S. I'm an Erudite but not a power-hungry one so don't panic.