You might feel, after considering utilitarianism and kantianism, that they are too extreme, too demanding, or too complicated. Maybe you are looking for a moral view that feels like something you could teach to children. When you first learned about right and wrong, you didn’t learn it by understanding some abstract principles, you learned that people matter, and that they deserve respect. Natural Rights Theory, the view that morality comes from people’s basic rights, is more like that. For a natural rights theorist, morally permissible actions are ones that respect rights, and morally impermissible actions are ones that violate rights.
You’re used to rights-talk from legal discussions. If you watch legal dramas like Law & Order, you’ll hear the characters talk about “right to due process” or “miranda rights”. In the news sometimes you’ll hear people talk about “right to free speech” or “privacy rights”. Those are all examples of legal rights that you have as a citizen of the United States. You get those rights from the government, or more specifically, from the Constitution. The government protects those rights as much as it can, and punishes those who violate rights as well as it can. If someone violates your legal rights, like for example your property rights (by stealing your property) they can be punished by the government under the law. But that’s not the case everywhere in the world. One government might grant its people the right to free speech, and another might not. So it might be within your rights to publicly criticize political leaders in the U.S., but you might be arrested for doing the same thing in Libya. That’s because the right to free speech is a legal right. You only have it as long as you are under the jurisdiction of a government that protects it.
But morality can’t be just whatever the government where you happen to live says it is. Besides, there are lots of things that are illegal in some places that are probably morally okay, and lots of things that are legally allowed in some places but are morally bad. For example, wearing a seat belt when you drive a car is legally obligatory, but is it morally obligatory? Are you doing something immoral if you don’t wear a seat belt? Of course, you’re doing something foolish, but it doesn’t seem to be morally wrong. Inversely, cheating on your boyfriend, girlfriend, or spouse seems pretty obviously wrong, but there’s no law against it. You can’t be arrested for cheating, but that doesn’t mean it’s morally okay. Also, since laws vary in different countries, and even in different states, what is legally permissible in one jurisdiction may be impermissible in another.
So moral rights have to be slightly different from legal rights. There have to be some rights that you would have even if the government where you live doesn’t protect them. There must be some rights that you would have even if there were no government—if you were in the middle of the ocean or on the moon. If there are some things that would be wrong, even if there is no government to declare them illegal, then you must have natural rights, not just legal rights. Saint Thomas Aquinas, a medieval Catholic philosopher, is usually considered to be the seminal thinker on the subject of natural law. He thought that all things, including people, have a “proper act and end”, meaning that there is a way that things are naturally supposed to be and this is where natural law comes from.
As stated above (Q. 90, A. 1, ad 1), law, being a rule and measure, can be in a person in two ways: in one way, as in him that rules and measures; in another way, as in that which is ruled and measured, since a thing is ruled and measured, in so far as it partakes of the rule or measure. Wherefore, since all things subject to Divine providence are ruled and measured by the eternal law, as was stated above (A. 1); it is evident that all things partake somewhat of the eternal law, in so far as, namely, from its being imprinted on them, they derive their respective inclinations to their proper acts and ends. Now among all others, the rational creature is subject to Divine providence in the most excellent way, in so far as it partakes of a share of providence, by being provident both for itself and for others. Wherefore it has a share of the Eternal Reason, whereby it has a natural inclination to its proper act and end: and this participation of the eternal law in the rational creature is called the natural law.
Aquinas thought that the eternal law was ‘imprinted on’ all things, and they act the way they do—they pursue their ‘proper acts and ends’—by obeying this eternal law. Another way to say this is that everything has a sort of purpose and a correct way of behaving. When people use reason to detect these purposes and they act in accordance with them, then they are obeying the natural law. Modern natural rights theorists would say that there are rights that people have just because they are people. For example, you might have a natural right to life, just by virtue of being alive. It would be wrong to kill you because it would violate that natural right. One of your ‘proper ends’ or purposes is to live. You might also have a natural right to freedom, since you also have a ‘proper end’ of freedom, so it would be wrong to hold you prisoner against your will.
According to natural law theory, the kind of laws that we’re used to thinking about (the ones issued by the government) would ideally be based on natural laws. Aquinas said that we humans use reason to discover the natural law, and then we make human laws that match up to it.
Accordingly we conclude that just as, in the speculative reason, from naturally known indemonstrable principles, we draw the conclusions of the various sciences, the knowledge of which is not imparted to us by nature, but acquired by the efforts of reason, so too it is from the precepts of the natural law, as from general and indemonstrable principles, that the human reason needs to proceed to the more particular determination of certain matters. These particular determinations, devised by human reason, are called human laws …
The legal rights that have now as citizens of the United States actually come from the idea that people have natural, moral rights. The authors of the Declaration of Independence, as an explanation of why the American colonies should become an independent nation, said “We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.”
They thought that it was morally wrong for the colonies to remain under British rule, even though that is exactly what was required by British law—the law that the colonists were under the jurisdiction of until that point—because they had the natural right to be free.
There are a lot of important things to notice in that sentence from the Declaration of Independence. First, they hold these truths to be self-evident—they thought it was obvious without any need for argument or evidence that all people have rights. They take that as given. Second, that the rights are endowed by their creator—they come from God, not from any government. And you don’t really need to use God here to explain rights. You can just say they come from nature. The important thing is that they don’t come from laws. Third, the rights are inalienable, which means that they can’t be taken away. Everyone has them, even if the government says they don’t.
The founders of the United States thought that people had natural rights, and that it was immoral to violate those rights. This model can give us a simple a way to determine what is morally permissible and impermissible. All we have to do is figure out what natural rights everyone has. Of course, that’s not as easy as it sounds. After we get through the obvious ones like life and freedom, there are some other ones you’d probably agree that everyone has, like property, privacy, and honesty, but eventually it’s going to get complicated. Does everyone have a natural right to work, to have children, to health care or education? If so, how can we guarantee that everyone’s rights will be respected? If not, when is it appropriate to deny those things to people?
Another problem with natural rights theory is that sometimes rights conflict. What if you’re starving and I own the only food around? Does your right to life outweigh my right to property? Is it okay to reduce people’s freedom (to spend their money) by taxing them in order to provide education to others? There are lots of cases we could imagine like this, and it’s not obvious how we should decide which rights should win out if there is a conflict.
One last problem for natural rights theory is that there are lots of moral questions we could ask that have nothing to do with rights, and the natural rights theorist has no way to answer them. Is it morally okay to exceed the speed limit? What’s wrong with being mean to servers at restaurants? Should I recycle? What right is violated or respected in those cases? It’s not clear what those questions have to do with rights, but I suspect that you don’t find them difficult to answer. This suggests that natural rights theory isn’t very useful in everyday situations.
 Aquinas, Thomas, Summa Theologica, Project Gutenberg edition, 2006, Part II-II, Question 91, Second article. http://www.gutenberg.org/cache/epub/17897/pg17897.html
 Ibid, Third article.