It is quite likely one of the least controversial of ethical questions: cannibalism. I say least controversial because most people agree that it certainly shouldn't be an accepted practice, and only if forced by threatened survival–and then, only if the eatee is already dead–would some resort to it. Pi has been faced with even this, and he, not surprisingly, succumbs.
I pray for his soul every day. (p. 322)
How strong is the will to survive that we can overcome all beliefs–including religious–to adapt ourselves to the situation at hand? I just took a couple of tests online about ethics and moral questions focusing on making choices of sacrificing one person for the many (recalling, of course, The Ones Who Walk Away from Omelas). There was no scoring, no commenting on my answers, yet I was anxious to see how I would have done. My own gut feelings were based on not being willing to trade one life for several, particularly in an ambitious and purposeful manner, though I lessened my standards on those that were not clearly of my own decision but rather as a possibility. My basis for choice was that while I am being told that to not risk the life of one, I am surely allowing the others to die, I don't accept that. But then, I never aced the "assume that" questions on tests either.
One thing I find interesting is that although Pi mentions his gods or his religions, even claims at one point to pray several times a day, and even though he states that his family is never out of his mind, I find that the story conflicts with this. There is likely a purpose to Martel's playing up of the religious aspect in the beginning of the book, but I'm not quite catching it here unless it is to prove that man's own nature sets his own ethical beliefs and values, without the need for a religious influence.