In Life of Pi agnosticism is represented by Pi's father, an entrepreneur now heading the Indian Pondicherry Zoo, while atheism is represented by Pi's biology teacher. Pi is ardent about science but he diverts from the non-spiritual feelings and beliefs of the two men he models his mind after and follows a spiritual path by studying and blending Hinduism, Islam and Christianity, while still embracing his father's pragmatism and his teacher's science. Just like the creatures who later occupy the lifeboat with Pi, these elements are all disparate and seemingly incompatible and there is the suggestion that perhaps some will devour the others, just like in the lifeboat, leaving only two to travel together until one deserts the other as the tiger deserts Pi.
Pi's father Santosh Patel, as the representation of agnosticism, is a practical and pragmatic man who is always looking for a way to improve his family's life. It is also why he chose to take his family and animals from India on a ship to Canada. In a highly symbolic and ambiguous novel, it may be that agnosticism is represented symbolically in the the sinking of the ship, if the ship represents the belief systems; and in the animals devouring each other in the lifeboat, if the animals represent all the disparate ideologies Pi has woven together; and in Pi's and the tiger's common sojourn on and joint flight from the algae island, if this represents how a belief system can exist compatibly with daily life; and in the tiger's abandonment of Pi with its eager run into the forest, if this represents the final value of a belief system at the end of life; and in Pi's made up story about the lifeboat survivors, if this represents the agnostics final dilemma of not knowing how to know.