Personal Identity

Course Overview

Suppose a mad scientist surgically removed your brain and transplanted it into your best friend’s body. Suppose that same scientist transplanted your best friend’s brain into your body. Given certain assumptions about how the mind works, and assuming these operations were successful, you’d each wake up with the same memories as before, but if either of you looked in the mirror, neither of you would recognize your new face as your own. It would be a medical miracle—you and your friend would have swapped bodies! But wait, is that even right? Maybe we should instead say that you and your best friend would each wake up with a completely different set of memories (i.e., those of the other person), and that you and your best friend would have swapped brains—or, better, minds. You would “remember” being your best friend, and your best friend would “remember” being you. Alternatively, perhaps at the outcome of the operation neither of the patients would be you (or your friend), and we should say that the operation resulted both in the deaths of you and your friend and in the creation of two distinct new persons.  

The question before us is the philosophical question of personal identity. Put more generally, this question asks what the “criteria” for personhood are, both at any given time (“In virtue of what relation are a person’s various properties the properties of the same person at a specific time?”) and across different temporal stages (“In virtue of what relation is a person at some given time the same person as a person at some later or earlier time?”). In this course we will be looking at a wide range of historical and contemporary texts that address these questions, as well as some fun examples from literature and movies.