Robert Nozick provided an argument against Utilitarianism called Experience Machine. The argument involves only the "Is" part: "We have reason not to plug into the experience machine." But this makes us think that people ought not to plug into the experience machine.
Same applies to other ethical theories:
- A virtuous human still may be wrong, therefore it's incorrect to rely only on virtues. So, we ought not to rely only on virtues.
- People strive for pleasure, therefore it's not only reason that drives people. Thus, morality is not measured only by duties. And we ought not to do it.
- It's impossible to predict consequences without some rules. Therefore consequentialism with no rules is wrong. And we ought to use some rules.
This can be expanded further, but I have no intention doing that. What I am asking is, is it really the case that the theory which has advantages (more objective) on descriptive part has advantages on normative part? Is it a good idea to use a more complete descriptive ethics as a foundation for normative ethics?
People use some kind of universal laws. Such laws like "do not murder", "do not steal", "do not rape", etc. These laws exist, because actions listed there can't be consensual (it is not stealing if you give a consent for someone to take your property). Therefore, we assume that consent is the basic principle when we act towards people. But surely, we should somehow punish guilty people, therefore consent is only required for acting towards innocent people. So, I formulate universal law of consent (of virtuous people): "Do not act towards innocent person without their consent".
How to decide if people give consent, if we acting towards person and what person is innocent is taken from intuitive people notions. Like, if your actions are not oriented towards people and their property, it's not covered with this law.
I placed "of virtuous people" because someone may point out crimes happen. But crimes are committed by non-virtuous people or either they are not really crimes (you may think someone who is beating another person is bad but rethink it when you acknowledge the person he is beating was offender).
Note, that all I say is "Is" part. Even my universal law, it's just a possible explanation what happens in society, like Relativity is possible explanation what happens in physics.
The principle is to show people facts about how decisions are made in society and let them themselves decide what they are ought to do. Like when you say in the game "This move will make you lose" and they themselves decide that they should make another move.