It can also be true that “we think this particular type of killing is wrong”. That agreement is, to use your phrasing, a "world-based notion of wrong”.
Ethics inherently involves how we are to deal with each other. It is our common ground. It is an ongoing discourse as to what we ought do. Your opinion is a part of that discourse.
What we have is a discussion concerning what we ought to do. Now how things are, or science, if you prefer, informs what we ought to do; but it doesn’t determine it.
Ethics is a dynamic, discursive conversation that interacts directly with what we do, and within which what you think we should do is for you the most important piece, but not the whole.
Another dimension: Ethics is not algorithmic. Ethics is far too complicated to have an algorithmic solution, moral decisions cannot be decided in an algorithmic fashion - they are far too complex. Just as no rule can accommodate the definition of ‘game’, no rules could cover the all possible situations we might call ‘moral’ .
Both consequentialism and deontology seek an algorithmic approach to ethics, as if such things were calculable. The enormous complexity of even the most simple decisions weighs heavily against such an approach. Treating a rule as absolute is giving succour to the devil, who will delight in inventing traps in which following the rule leads to cruelty.
Virtue ethics may be the better fit, precisely because it resists algorithmic treatment.
Heuristics are a central part of virtue ethics, their use following more directly there than from either consequentialism or deontology. The point of virtue ethics was to avoid rules, but along with Anscombe, to treat ethics as closer to conceptual analysis. Virtue ethics better suits ethical problem solving once one agrees moral issues are solved "heuristically, not algorithmically.
Even so no criteria, even in virtue ethics or capability frameworks, that will work in all cases for all questions; and yet we have to do the evaluation, so we use an iterative process, in which each iteration changes the rule being iterated. So the list of virtues and the list of capabilities changes over time. This leaves the meta-question “What is the way we settle these matters?” open, answered only reflexively: “that’s part of these matters”.
But “not algorithmic” does not mean “not rational”. Buridan’s Ass shows that sometimes an arbitrary choice can still be rational. Buridan’s Ass will die unless it makes an arbitrary decision, and hence sometimes it is rational to make arbitrary choices. The alternative to algorithms is not relativism but better decision-making and self-cultivation. The only viable response is to seek to make good decisions; to make oneself a better person.
What ethics is fundamentally about is action, not passive rule-following or experience. Ethics is fundamentally about how one relates to others, how one acts within a community.
Ethics resists algorithmic/rule-based treatment because of the complexity and variety of situations; virtue ethics is favoured as better suited to this non-algorithmic character; but even virtue-based criteria, lists of virtues and capabilities, are themselves revisable through an iterative, non-foundational process rather than fixed by a further algorithm.
Not what folk want. They want a rule. The engineers will be especially miffed. Tough. Learn to adult. “I think this particular killing was wrong” is a good place to start.
