Editing Derek Parfit (section)

=== ''On What Matters'' ===
{{main|On What Matters}}
In his second book, Parfit argues for [[moral realism]], insisting that moral questions have true and false answers. Further, he suggests that three categories of ethical theory—[[Immanuel Kant|Kantian]] [[deontology]], [[consequentalism]], and [[contractualism]]—converge on the same answers to moral questions.<ref>{{Cite web |last=Gutting |first=Anastasia |title=On What Matters, Volumes 1 and 2 |url=https://ndpr.nd.edu/reviews/on-what-matters-volumes-1-and-2/ |archive-url=http://web.archive.org/web/20240703202631/https://ndpr.nd.edu/reviews/on-what-matters-volumes-1-and-2/ |archive-date=2024-07-03 |access-date=2025-01-12 |website=Notre Dame Philosophical Reviews |language=en-US}}</ref>

In the conclusion of the third volume, published shortly after his death, Parfit writes that the affluent have strong moral obligations to the poor:

<blockquote>One thing that greatly matters is the failure of we rich people to prevent, as we so easily could, much of the suffering and many of the early deaths of the poorest people in the world. The money that we spend on an evening’s entertainment might instead save some poor person from death, blindness, or chronic and severe pain. If we believe that, in our treatment of these poorest people, we are not acting wrongly, we are like those who believed that they were justified in having slaves. 

Some of us ask how much of our wealth we rich people ought to give to these poorest people. But that question wrongly assumes that our wealth is ours to give. This wealth is legally ours. But these poorest people have much stronger moral claims to some of this wealth. We ought to transfer to these people [...] at least ten per cent of what we earn.<ref name=":3">{{Cite news|last=Matthews|first=Dylan|title=The whole philosophy community is mourning Derek Parfit. Here's why he mattered.|newspaper=Vox|url=https://www.vox.com/science-and-health/2017/1/3/14148208/derek-parfit-rip-obit|access-date=2017-01-06}}</ref> </blockquote>He also concludes that responding to risks to humanity's survival is what "matters most", with humanity's descendants or successors having the potential to spread through the galaxy and create unprecedented good over billions of years.<ref name=":3" />