The series raises a lot of philosophical questions about human nature, What does it mean to be human? How humans relate to the environment, and whether human standards of morality can be applied to other species.. Migi, is motivated by survival instinct. It's acceptable to kill if it means sustaining himself. He's not driven by any emotion. Migi always tells Shinichi that humans do the same. They kill animals and eat them. They even harm other humans to advance their interests. What difference does it make for a parasite to do the same? Why when a superior being feeds on humans it's considered wrong? What makes it wrong/ immoral when humans do the same? This question wasn't completely resolved in the show Though.
Review of Parasyte: The Maxim
