I am generally deeply suspicious of normative ethical theories. I think ethics is hard, and attempts to simplify it to a set of rules inevitably have the problems that taking a complex space and making it legible always do. They're potentially a useful mental tool, but as soon as you start arguing about which one is true you've lost. Even if I was a moral realist, which I'm not, it seems obviously the case that the ethics that can be told is not the true ethics.
So obviously I thought it might be an interesting experiment to set out to build one. The following is part of what I came up with. This is something I at most weakly believe. I think it's a good model for evaluation of actions, but I don't think it's one I would actually attempt to follow dogmatically.
You have one duty: The world and all that is in it should thrive. Things should get better over time, not worse.
You have four duties: To yourself, to those around you, to humanity, and to the world.
Until you have fulfilled the earlier duties, you should not consider the later.
- Your duty to yourself is that you thrive.
- Your duty to those around you is that you help them thrive.
- Your duty to humanity is that your existence should help rather than hinder it in thriving.
- Your duty to the world is that your existence should help rather than hinder it in thriving.
Each duty supersedes the later ones: Ensure you thrive, then others around you, then humanity, then the world. This does not mean that you should always prioritise yourself above others, but it does mean that you should put your oxygen mask on first before helping others with theirs.
To live a good life is to discharge your duties to the best of your ability. There is no shame in failing to uphold these duties because you are unable, only because you are unwilling.
(I originally had a bunch of text explaining the reasoning behind this, but actually this is more intended as an interesting artifact than something I'd propose to defend, so I just deleted it).