What does these quotes mean from the book Life of Pi?
"For evil in the open is but evil from within that has been let out. The main battlefield for good is not the open ground of the public arena but the small clearing of each heart."
"I must say a word about fear. It is life's only true opponent. Only fear can defeat life."
One of the remarkable aspects of this story is the number of highly thoughtful and often provocative quotes that it contains as Pi shares with us his strange experience and what he learned as a result. The first quote you have selected points towards the way that the evil forces that we face in our lives have actually all emerged from within us. The focus on the "small clearing of each heart" as the "main battlefield for good" argues that evil is an internal force that must be fought internally and triumphed over not externally but within our hearts. This is of course a particularly interesting quote when we remember the allegorical nature of the central tale and when we question the identity of Richard Parker and if he was actually some form of projection of Pi himself.
Secondly, Pi should definitely know all about fear from his experiences of being stranded on a boat for so long. Fear in this quote is set in opposition to life, and we are told that it is the "only true opponent" of life. This of course speaks of Pi's desperate struggle to cling on to life and not give in to the force of fear, no matter how bad things get in his life and no matter how his situation worsens.