the notion of philosophical zombies, theoretical creatures identical to human beings with one tiny distinction - they have no consciousness, qualia, or sentience. Imagine a twin who is identical to you in every possible material way but lacks any type of inner subjective experience. Clearly something is different between the two of you, but how and why?
Many would simply cite the existence of rationality and self-awareness - things we associate with the mind. But what exactly is the mind, and how is it distinct from or similar to the brain? For that matter, how important to our humanity are the immaterial aspects of our nature - our consciousness, our mind, our thoughts, ideas, and emotions? And is there a philosophical system sufficient to explain them?
In The Walking Dead and Philosophy, two introductory essays (“Are You Brains or Something More?” by Gordon Hawkes, and “Can You Survive a Walker Bite? “ by Greg Littmann) attempt to tackle these important questions.