Utilitarianism (from the Latin utilis, useful) is a theory that prescribes the quantative maximization of good consequences for a population. It is a form of consequentialism. Though some utilitarian theories might seek to maximize other consequences, these consequences generally have something to do with the welfare of people (or of people and nonhuman animals). For this reason, utilitarianism is often associated with the term welfarist consequentialism.
There's a huge problem. Utilitarianism is completely revolved around the ends, and ignores means altogether. Thus, Utilitarianism jumps to "the ends justify the means" conclusions. But that means that any ethical standard goes out the window as soon as a presumed "good" consequence appears achievable. However, no matter how "good" a consequence may seem, it does not negate the question of the means to such consequences. Modern political talking points such as "we have to fight them there so we don't have to fight them here" and "we have to have a huge social safety net or millions of people would starve to death" is pure utilitarianism.
Instead of starting on a results-based ethic, how about using a real axoim to determine right and wrong? The non-aggression axoim. Natural law. Everyone is free to choose, act and think without harming the person or property of others. You would think that such a contention as non-aggression would be common sense - it's in practically every religion and philosophy known to man in one form or another. Every single view on an issue I take stems from that. It's that simple. The difference between me and many others is that I apply the golden rule to government itself. I don't give government a double standard, I consistantly hold all individuals and groups to the exact same ethical standard.
If it's wrong for Joe to murder Jack, it's wrong for people acting on behalf of the government to murder Jack as well. Immediately we come to the grounds for being anti-war - war is mass murder. The ends don't justify the means. If it's wrong for Joe to steal from Jack, it's wrong for people acting on behalf of the government to steal from Jack as well. In theory, immediately we come to the grounds for not exactly being fond of taxation - the act of taxation itself is not really separable from theft. The ends don't justify the means. Even if you tell me that the thief then gives money to the poor, or any good thing, the initial act of theft is still wrong. If a robber made an arguement in court that their act of theft is justified by the boost in retail that their spending of the stolen money produced, they would be laughed out of court.
The utilitarian anarchist could conclude that because criminal means are the most efficient or easy way of achieving the results that they desire, they are justified in commiting violations of people's liberty in the name of attaining their desired ends. But while the individual would obviously not be justified in such action, neither would a government or any group within society. It is a curious social phenomenon that while the vast majority of people would condemn the individual for using unjust means to easily achieve an end, they apply a double standard to the government to the extent that the government is allowed to do the very same thing that everyone recognizes as being blatantly wrong when done by a citezen.
Thus, we see a political atmosphere in which people are convinced that their particular desired ends should be sought out no matter what the means are, wether their desire is to reduce crime, make people moral, stabalize the middle east, help the needy, or make us "secure" and enlightened. In the name of achieving presumably good things we use means that are absolutely "evil" by all common sense ethical standards. To make a doctor analogy, the result is often that you kill the patient in the name of curing their disease. Often, the desired ends don't even become a reality, and it becomes even worse then "the ends justify the means", it becomes "the goals/intentions justify the means".
Most of the arguements between libertarians and other groups revolve around the libertarian pointing out that the means are unethical. Then the utilitarian points to the ends to try to justify it, and the libertarian repeatedly asserts that the ends are irrelevant, they do not cancel out the ethics of the means. That's why I despise utilitarianism. It's all about ends and ignores means. It "justifies" unethical things by making an arguement of results. I declare that the results are irrelevant if the initial means violate liberty. The ethics never go out the window. I don't dispose of right and wrong because of results. If the right thing doesn't lead to perfect results, I still support it. If the wrong thing leads to presumably good results for a particular group, I still oppose it. There is no double standard.
Take something like "Click It Or Ticket" laws for example. What the law essentially does is coerce people to put on their safety belts, backed up by the force of a man with a gun, and if they are "caught" they are fined by the state. While that force of the bayonette may not be used, the threat of that force is unethical all the same. The fining of the person for the "crime" of not being safe is unethical all the same. Some proponents of such laws may point to statistics demonstrating that deaths and injuries from car accidents are down ever since such laws were put into place (which is misleading nonsense in the first place: compulsion does not stop harm in accidents, the seatbelt does). Even if true, it is irrelevant to the ethics of the matter - it does not justify the use of coercion to force people against their will to act in a particular manner, nor does it justify stealing their money for not taking such precautions. The ends do not justify the means - the law is unjust, in violation of personal (the compulsion) and economic (the fine) liberty, no matter what results it leads us to.
Often, when debating about economic issues and capitalism, people make utilitarian arguements about the results of wealth and poverty. The question is of the means to wealth and poverty. Not the end results themselves. The terms of the means is what needs to be defined. Was the wealth achieved through force? Then it is not legitimate. Was it achieved voluntarily? Then it is legitimate. Was the poverty created by force? Then it is not legitimate and should be corrected. Was the poverty created naturally, voluntarily? Then it is unfortunate, but not legitimate to use force in reaction to it.
It all goes back to the economic and political means to wealth. If it's the voluntary, economic means to wealth - then, regaurdless of results, it is legitimate. If it is the coercive, forceful political means to wealth - then, reguardless of results, it is not legitimate. The question about income disparity is irrelevant if we do not address the means to that disparity. "Is income disparity good or bad" is not a fair question, because it ignores the question of the means.
Income disparity naturally exists to begin with. That type of income disparity is not only not a crime, but is necessary for the division of labour. Politically created income disparity is what is not legitimate. But the natural voluntary disparity between people who have better and lesser achievements is something that is going to always exist until the end of time, as an intinsic part of human nature, and it presents no ethical violation.
And thus, we get to why socialism is bad news. It tries to "cure" that natural disparity through the use of the political means. It considers human nature, the natural differences between individuals, to be "evil". It tries to change something that cannot be changed - human nature. It demonizes those that have achieved their status and sucess voluntarily as if it is some kind of crime against humanity (the irony being that it IS humanity), and thus sets out to cripple the economic means to wealth. Why's communism bad? Because it's based on hatred for the natural division of labour and tries to abolish it through forceful means.
The same goes for fascism and neoconservatism, for different matters. It seeks to justify the mass-murder of countless people by making arguements about "democracy" and "peace" and "freedom". It seeks to justify making innocent people into criminals through victimless crimes by making arguements about "order" and "tradition". It argues that alleged "security" brought through a surveillance state somehow negates the loss of liberty it requires. It argues that making everyone pay to keep an innocent and non-violent person in jail for something like drugs, and the loss of liberty such prohibitions require, is somehow justified by the end of isolating such people from the rest of society.
Where communism cannot accept the natural economic divisions, reactionary rightism cannot accept the natural social/personal divisions. Both abandon principle in the name of seeking desired ends that are either impossible to achieve or do not justify the means. People from all over the political spectrum tend to make the mistake of defining their rights as a gaurantee of a particular result, without realizing that the means used in the name of achieving such goals often violate their rights in the first place. Even if they do achieve their desired ends, it was achieved through unethical means. I'm no Christian, but what about "Don't Kill" and "Don't Steal" don't people understand?
Utilitarianism is an ideology that abandons values in the name of people's innermost fantasies. Liberty should never be sacrificed in the name of the desire for results. Both personal and economic freedom is not expendable. Right and wrong is not a gaurantee of results, it is a matter of the means to a given result. True liberty depends on adhering to non-agression consistantly. Any deliniation from that will lead to a violation of liberty. It's a sad fact of life that governments tend to violate liberty with a promise of results, and it attempts to justify its unethical actions by pointing to short-term results that may appear to be "good" while ignoring principles. Utilitarianism is the perfect tool for tyranny to attempt to justify itself to its subjects.