The personality theory is revised to state that the key to personal identity is having the same personality provided that there is no branching, that is, provided there is no transfer or duplication of the same personality from one body to another. Similar "no branching" requirements are added to the other theories as well. At the end of class, Professor Kagan suggests a shift from thinking about the survival of the soul in terms of "what does it take to survive?" to "what is it that matters in survival?".