(1) Why should I act? Why should I do anything at all? What is the, my, overarching purpose? The purpose that functionally guides my actions in life?
(2) An externally imposed telos would be convenient. But it requires belief in some external. And anyway is inadequate. The problem of purpose shifts one to the left, just like the problem of first cause.
(3) The challenge then is to create a meaningful, well-founded, objectively defensible purpose in life ex nihilo. Let's begin.
(4) The universe has no intrinsic purpose. The things that happen in it don't have meaning just because they happen. No particular configuration of atoms is intrinsically better than any other. This means that no outcome has independent, intrinsic value in and of itself.
(5) I experience joy, pleasure and happiness from present events. I eat the chocolate because it tastes good now. Immediate phenomenological consequences.
(6) Contingent events. I decide to go for a run because I know I'll feel good once I've got going, because I'll be happier if future me is fitter. I do something unpleasant now to help someone because I know it will feel good to have helped them. The same immediate phenomenological consequences.
(7) Joy, pleasure, happiness are only serotonin, dopamine, particular neural patterns. Positive emotions are just particular configurations of atoms. But I perceive and I value those patterns. And preferences are also just particular configurations of atoms. So/and/but they are just as real as everything else.
(8) Conscious preference is a purpose. Conscious preference is hedonism. And hedonism is a very individually constrained purpose. It allows for purely selfish indulgence with no direct regard for others.
(9) It may be nothing more than social conditioning or the absence of psychopathy, but unalloyed selfish indulgence has an unpleasant aftertaste. Sadism would be no fun if the masochist was unwilling. And the expectation and reality of joy after doing something for someone else is also real.
(10) From this alone, hedonism as a purpose is broader than personal selfish pleasure in the moment. Yet it remains a fundamentally self-only purpose. Is it possible to establish a purpose with broader relevance?
(11) Descartes argues we shouldn't assume the existence of anyone else. Cogito ergo sum. And without further assumptions it may be that hedonism is the only overarching purpose.
(12) But let's assume that other minds exist. Cogito ergo sum. Cogito ergo nos omnes sumus.
(13) If my joy has value then so does theirs. Concomitantly the alleviation of disjoy. Helping others is still selfishly purposeful. But it is also selfless.
(14) Helping others be joyful and helping others avoid disjoy is very broad. Can I rank order specific different activities?
(15) Helping others directly and being able to see the positive impact of that help generates the greatest personal self-satisfaction. Psychological evidence suggests we value avoiding disjoy more than we value attaining joy.
(16) Second- and n'th-order effects are important. Exponentially enabling joy and exponentially mitigating disjoy has a greater impact on the universe. From the perspective of the universe more is better.
(17) If it was going to happen anyway then the impact is marginalised. Joy credit only for the delta between what did happen / was averted and what would have happened / would have been averted. Also delta when.
(18) Joy and aversion must be noticed to be real. The more they are noticed the more real they are. Mindless eating of tasty food is bland.
(19) This is a conclusion. Help as many as possible. Help as many help as many as possible. Help where help would not otherwise be given. Enable visibility of the joy and aversion, enable others to enable visibility of the joy and aversion. All else equal, prevent disjoy, then generate joy.
(20) Many concrete candidates. Happiness engineering. Teaching life skills. Teaching to teach. Encouraging prosociality. Community support. Systematic societal compassion and kindness. Individual communication. Non-violence. Stoicism. Evolutionary engines with feedback loops and network effects. Climate resilience. Companionship. More thinking needed to select specifically. But something is better than nothing.