Reasons and Persons by Derek Parfit is an argument for being more objective and less personal in our decision making.
In the first few chapters Parfit constructs a concept of morality that asks two questions:
- How likely are you to sacrifice your happiness for the happiness of someone else?
- How likely are you to sacrifice your present happiness for your happiness in the future?
Later in the book he describes a theory of personal identity that asks two questions:
- How connected are you to someone (or even yourself) psychologically?
- How connected are you to someone (or even yourself) physically?
A question Parfit keeps raising is whether you are really the same person as you were 10 years ago. Most of the thoughts in your brain are completely different as well as nearly every atom that makes up your physical body. What makes you you? He raises a series of teleporter thought experiments. If you teleported to Mars would the person on Mars be the same person on Earth? What if the teleporter malfunctioned and you were duplicated? What version would actually be you?
This book has led me to think that perhaps the boundaries between people is a bit less than I thought. It's led me to question how to maximize the happiness of more people and not just people in the present but people in the far off future as well. It's led me to let go of things that I've done in the past and give myself more permission to invent a different version of myself in the future.