Far be it from me to argue with the 230-year-old document that forms the basis of our government, but there are several problems with this line of reasoning. First, it's very difficult to find passages in the Bible and other sacred texts that describe unalienable political rights. Second, an argument on religious grounds is unconvincing to those who do not share one's particular religious beliefs. Third, governments grounded in specific theological beliefs tend to violate unalienable rights. Fourth, human rights have been protected for a variety of other reasons that have nothing to do with religion. And fifth, most importantly, the idea of rights that stem from natural law gives nature more credit than it deserves.
The author of the Declaration, Thomas Jefferson, was well-versed in political philosophers of the European Enlightenment. Among the first and most widely read was Thomas Hobbes, author of Leviathan (1651), who proposed that natural rights existed because they were fundamental to our nature. Everyone wants life, liberty, and happiness; they are part of who we are as animals; and therefore it is contrary to nature, arguably contrary to the will of God, to deny us those rights needlessly. Hobbes argues that we do choose to give up some of our natural rights so that we may participate in larger society, but even in this we only sacrifice smaller goals to improve our own quality of life. To live without society, or in conflict with society, is to live a life that is (in Hobbes' words) "solitary, poor, nasty, brutish, and short." That certainly doesn't seem consistent with the pursuit of happiness.
But there are some basic problems with this idea. First, there are things in our nature as a species that are most certainly not natural rights. The evolutionary record tells us that we are meat-eaters, genetically programmed killers who have more than likely driven other primate species into extinction with our selfishness and our superior capacity for violence. There are elements of this violence and selfishness that are intrinsic to who we are. In rejecting this we become better human beings and we increase our own prospects for a long and happy life, but we do so by intentionally suppressing the nastier aspects of our nature. We rebel against much of who we are, in other words, when we make love and empathy the guiding principles of our lives.
So the very concept of rights stemming from natural law is problematic. We strive for empathy; nature is indifferent. We strive for love; nature is violent. We strive for inclusion; nature excludes. We strive for a better world; nature teaches us to exploit it. Natural law is a poor foundation for natural rights. But does this mean we don't have any rights at all?
No, but it does make the idea a little more complicated. One of the benefits of the natural law theory of rights is that it implies that everyone has the same rights, always, and that these rights never change. That consistency is appealing. If we reject it, then rights become more fluid--things that we create--and therefore subject to change. The great American biologist Ken Hudgins once wrote that "the meaning of life is to give life meaning"; in a world where we can't look to nature to tell us what our rights are, we have to find them in our shared values. And let's face it: That's what we tend to do anyway. We believe that rights exist because we care enough about people to respect their livelihood and their autonomy.
Let's take the abortion debate, for example, because it's so easy to understand. Anyone who cares about women surely believes that women have the right to make decisions about their own bodies, but some of us also believe that embryos and fetuses are full human beings--tantamount to infants. The idea of killing infants is something that none of us would be willing to tolerate, no matter how much we love women, so those who see no difference between fetuses and infants are going to want to do all that they can to prevent abortion regardless of how much they care about women. Those of us who don't see fetuses as tantamount to infants don't care as much about them, so we are concerned only about the women who bear them.
Or we could look at free speech. As much as we might talk a good game about how much the free exchange of ideas benefits society, I suspect most of us, when you get down to brass tacks, support free speech because we care about our fellow human beings too much to want to see people punished just for expressing ideas. We support freedom of religion because we care about our fellow human beings too much to want to see them imprisoned for what they believe. We support the right to protection from cruel and unusual punishment because we care about people, even prisoners, too much to want to see them suffer more than necessary. We care about the right to a trial by jury because we care about people too much to want to see the innocent go to prison.
And it is our love, our empathy, our capacity to care that leads us to suppress our natural tendencies towards selfishness and violence. Nature and rational self-interest, for most of us, don't have much to do with it. The idea of natural rights, like most worthwhile ideas, is a product of empathy and love--not an axiom of nature comparable to the laws of physics. We protect the rights of ourselves and others because we care. Nature, which is indifferent to our rights and struggles, has nothing to do with it.