Reasons and Persons

Reasons and Persons by Derek Parfit

This is a long book that explores ethics and morals. What makes something ethical? Sometimes there appear to be simple situations. Then there are complex situations. The temporal dimension adds many challenges. Would you do something now that negatively impacted you of the future? Can you complain about those of the past since you would not be there without them? What should you do for the future? How does this differ from impacts of other people? There are challenges with many different philosophical theories.

A big section of the book explores science fiction topics. What entails your identity? If you have a device that transfers you to a different place by reading your body and reassembling it elsewhere, is that new person you? What if both the old and new are maintained? What if there are small changes made to you?  There are challenges for multiple definitions of "sameness"

There are a number of interesting arguments here, though it does go on for a long time.