The question needs to cover how one should act in all situations, simply because we want to answer the question. Otherwise we’re left without guidance and with uncertainty.
Well first, we normally don’t think of questions like which clothes to wear as being moral. Secondly, we’re not left without guidance when morality leaves these issues alone: we have pragmatic reasons, for instance. Thirdly, we will always have to deal with uncertainty due to empirical uncertainty, so it must be acceptable anyway.
There is one additional issue I would like to highlight, an issue which rarely is mentioned or discussed. Commonly, normative ethics only concerns itself with human actions. The subspecies homo sapiens sapiens has understandably had a special place in philosophical discussions, but the question is not inherently only about one subspecies in the universe. The completeness criterion covers all situations in which somebody should perform an action, even if this “somebody” isn’t a human being. Human successors, alien life in other solar systems, and other species on Earth shouldn’t be arbitrarily excluded.
I’d agree, but accounts of normativity which are mind- or society-dependent, such as constructivism would have reason to make accounts of ethics for humanity different from accounts of ethics for nonhumans.
It seems like an impossible task for any moral theory based on virtue or deontology to ever be able to fulfil the criteria of completeness and consistency
I’m not sure I agree there. Usually these theories don’t because the people who construct them disagree with some of the criteria, especially #1. But it doesn’t seem difficult to make a complete and demanding form of virtue ethics or deontology.
Well first, we normally don’t think of questions like which clothes to wear as being moral. Secondly, we’re not left without guidance when morality leaves these issues alone: we have pragmatic reasons, for instance. Thirdly, we will always have to deal with uncertainty due to empirical uncertainty, so it must be acceptable anyway.
I’d agree, but accounts of normativity which are mind- or society-dependent, such as constructivism would have reason to make accounts of ethics for humanity different from accounts of ethics for nonhumans.
I’m not sure I agree there. Usually these theories don’t because the people who construct them disagree with some of the criteria, especially #1. But it doesn’t seem difficult to make a complete and demanding form of virtue ethics or deontology.