The minimum complaint theory states that we should choose the options that generate the least amount of valid complaints. It is probably the strongest ethical theory in the sense that it is most preferred by everyone, is the easiest to defend against objections and complaints, and maximizes respect for autonomy.
In ethics we have to choose between different options. Options can be situations or moral rules. Our choices have an effect on persons. I define a person generally as someone who has subjective preferences, i.e. a sentient being who is able to value options and want certain options. A complaint measures how strong an affected person prefers his or her most preferred option above the actual chosen option. The less an affected person prefers the actual chosen option over another option that one could choose, the stronger that person can complain. We have to choose the option where the total sum of everyone’s strongest complaints (the total amount of complaint) is minimized.
There are three cases where a complaint becomes less valid or invalid: existence, externality and exclusiveness problems.
1) Existence problems. Some options (e.g. procreation choices) determine who will exist. A person who exists in an actual chosen situation can have a positive preference for that situation in the sense that that person in that situation prefers the actual chosen situation above a situation in which that person does not exist. A complaint becomes invalid if the complainer is in a situation in which the complainer has a positive preference (i.e. prefers existence above non-existence) and if all other possible situations that have a smaller total complaint are situations in which the complainer does not exist. (As soon as a person is born, the situation in which that person does not exist becomes impossible.)
For example: suppose we can choose between the births of new people versus the non-existence of those possible people. Suppose the already existing people are indifferent between those two choices. If we choose the situation where the potential new people do not exist, those people will have no complaints (non-existing people have no preferences and hence no complaints). On the other hand, if the new people are born and hence exist, it is likely that there will always be some complaints. There may be no situation that is most preferred by all those newborn people. For example every newborn person can have a highest preference for the situation in which that person gets all the resources, but then other persons will complain. So in any chosen situation in which those people exist there is always at least one person who would prefer another situation. That means there is at least some complaint. If those people prefer that those complaints are valid and that we should take them into account, we will have to choose the situation where those people do not exist, because that is the situation that minimizes their complaints. If that is not preferred by those people, their complaints are invalid.
A situation where a group of people exist who all have a positive preference and wherein the total complaint of all those people is minimal, is as good as a situation in which that group of people does not exist, provided that the preferences of other individuals outside of that group are the same in all situations (i.e. they are indifferent between all possible options). All other situations in which that group has a greater total complaint are less good.
A complaint can also become less valid if the complainer is in a situation in which the complainer has a positive utility and when minimizing the total complaint is more likely to result in a sadistic conclusion, i.e. when minimizing complaints has a higher risk of choosing a situation where the complainer does not exist and where other people have a lower average utility than the utility that the complainer has in the situation where the complainer exists and has a complaint. This theory corresponds with person affecting utilitarianism in population ethics.
2) Externality problems. Some options (e.g. some choices for moral rules or rights) generate negative externalities or costs on others. For example if we choose to give everyone a right not to be harmed, the mere presence of a person with that right can decrease my liberty and hence generates a negative externality for me. Suppose I am in danger and I want to save myself, but someone else is in my way. I can only save myself by doing something that will harm that person. If the person would not have been there, I could justifiably save myself, but the presence of that person with the right not to be harmed means I no longer have the liberty to save myself. However, there is one fundamental right that does not generate such negative externalities: the basic right not to be used as a means against ones will. Suppose I want to use you against your will as a means to my ends. You can complain, because that use is against your will. So you could propose a basic right not to be used as a means against ones will. A person is used as a means to an end if the presence of that person is necessary to achieve the end. I could complain that with this right I am no longer able to reach my ends. But this complaint becomes less valid or invalid when we consider the fact that if you were not present, I could not reach my ends either. It makes no difference to me if you are not present or if you are present and you have this basic right. Your presence does not pose negative externalities on others when you have that basic right. Complaints against moral rules (e.g. against the choice for a specific right) become less valid when the mere presence of people who are subject to that moral rule does not pose any negative externalities (costs, loss of liberties) on others. Therefore we cannot complain against the basic right not to be used against ones will. As a result, a complaint becomes less valid when the complainer wants to use other persons as means against their will and is not allowed to do so because of this basic right. This results in a deontological rights-based ethic.
3) Exclusiveness problems. Some options are about permissions and prohibitions. If you may do something, everyone else may do similar things. Your permission or right to do that thing does not belong exclusively to you. If you are allowed to do something, then so is everyone, because you are not special. You should not arbitrarily pick yourself from the set of all individuals and say that you are the only one who may do that thing. You are not allowed to exclude other people from following the rule that you follow. If you do something according to a rule, that rule does not apply exclusively to you. You have to ask the question whether you can consistently want that other people do similar things (in particular follow the same rules) that you do. You can consistently want something only if that what you want is not in contradiction with a consistent set of all the most important things that you want or prefer, such as your strongest moral values. For everything you do, you have to be able to give a moral rule that justifies your act, and you must be able to consistently want that everyone follows that rule. If you cannot give such a rule, your act is not allowed. If you are prohibited to do something, you can complain. But a complaint becomes invalid if the complainer is prohibited to do something on the basis that the complainer is not able to give a moral rule of which the complainer can consistently want that everyone follows that rule.
For example: if you do not take the complaints of other sentient beings properly into account, other people do not have to take your complaints into account. You cannot consistently want that, so you should take the complaints of others properly into account. If you are forced to take the complaints of others into account, your complaint against that enforcement is invalid. Similarly, if you enforce your preferences (e.g. moral principles or values) on others in a way that generates valid complaints, others may enforce their preferences on you. You cannot consistently want that and you cannot validly complain against that. Therefore you should not enforce your preferences on others unless they minimize valid complaints. This demonstrates that the minimal complaint theory is very coherent. The non-exclusiveness principle corresponds with the anti-arbitrariness principle that states that we have to avoid unwanted arbitrariness (i.e. arbitrariness that generates valid complaints).