Marriage and Fundamental Physics

Among other important elections, on November 4 Californians will be voting on Proposition 8, a measure to amend the state Constitution in order to ban same-sex marriages. The polling has been very close, with a possible late break toward a “Yes” vote; this would effectively overturn a California Supreme Court decision from this May that held that same-sex couples had a right to marry under the equal protection clause of the California Constitution. Eventually, of course, gay marriage will be accepted throughout the country, and we will look back on today as the bad old days of discrimination. But that’s cold comfort to the couples who would like to celebrate their love for each other right now. You can donate and learn more about the measure at No On 8.

We are occasionally asked why a Physics Blog spends time talking about religion and politics and all that nonsense. A perfectly correct answer is that this is not a Physics Blog, it’s a blog by some people who happen to be physicists, and we talk about things that interest us, blah blah blah. But there is another, somewhat deeper, answer. Physics is not just a technical pastime played with numerical simulations and Feynman diagrams; nor is it a purely instrumental technique for unlocking Nature’s secrets so as to build better TV sets. Physics, as it is currently practiced, is a paradigm for a naturalistic way of understanding the world. And that’s a worldview that has consequences stretching far beyond the search for the Higgs boson.

Charles Taylor makes an admirable stab at a very difficult task: understanding the premodern mindset from our modern vantage point. (Via 3 Quarks Daily.) There are many ways in which our perspective differs from that of someone living five hundred years ago in a pre-scientific age, but Taylor emphasizes one important one:

Almost everyone can agree that one of the big differences between us and our ancestors of five hundred years ago is that they lived in an “enchanted” world, and we do not; at the very least, we live in a much less “enchanted” world. We might think of this as our having “lost” a number of beliefs and the practices which they made possible. But more, the enchanted world was one in which these forces could cross a porous boundary and shape our lives, psychic and physical. One of the big differences between us and them is that we live with a much firmer sense of the boundary between self and other. We are “buffered” selves. We have changed.

Our ancestors lived in an enchanted world, where the boundary between the physical and the moral and the spiritual was not very clearly drawn. It made perfect sense, at the time, to attribute to the external world the same kinds of meanings and impulses that one found in the human world — purposes, consciousnesses, moral judgments. One of the great accomplishments of modernity was to construct a new way of understanding the world — one based on understandable, formal rules. These days we understand that the world is not magic.

This change in perspective has led to extraordinary changes in how we live, including the technology on which we are sharing these words. But the consequences go enormously deeper than that, and it is no exaggeration to say that our society has still not come fully to grips with the ramifications of understanding the world around us as fundamentally natural and rules-based. That’s the point at which the worldview suggested by science has had a profound effect on moral reasoning.

For our present purposes, the most important consequence is this: notions of “right” and “wrong” are not located out there in the world, waiting to be discovered, in the same sense that a new kind of elementary particle (or even a new law of physics) is located out there in the world. Right and wrong aren’t parts of the fundamental description of reality. That description has to do with wave functions and Hamiltonian dynamics, not with ethical principles. That is what the world is made of, at a deep level. Everything else — morality, love, aesthetics — is up to us.

Which is not to say that moral concepts don’t exist. It’s just that they are things we construct, not things that we come to understand by examining the world around us. To Plato or Aristotle, as well as their Medieval followers, the kinds of reasoning used to tackle moral questions wasn’t all that different from that used to tackle questions about the natural world. One looked at the world, noticed that certain things seemed to serve certain purposes, and (somewhat presumptuously) elevated those appearances to laws of nature. Some sort of conception of Natural Law has been an important strand of philosophical thinking all the way through to the modern era, even showing up in the Declaration of Independence (“We hold these truths to be self-evident…”).

But it’s wrong. There aren’t Natural Laws that distinguish right from wrong in human behavior. There are only Laws of Nature, which can account for the behavior of the complicated chemical reactions that make up human beings, but stand strictly silent about what those human beings “should” be doing. Things happen in the world, not because of any underlying purpose, but because of the combination of initial conditions and the laws of physics. The fundamental category mistake underlying the idea of Natural Law should have become perfectly obvious and universally accepted in the years after the scientific revolution, but it stubbornly persists, because people want to believe it. If the laws governing right behavior were inherent in Nature, waiting to be discovered, everything would be so much easier than if we have to work them out ourselves.

Just because moral instructions are not located out there in the world, immutable and awaiting discovery, doesn’t mean that “anything goes.” It means that moral guidelines are invented by human beings. Too many people fear that if this sort of moral relativism is true (which it is), then there is no way to denounce Hitler or Charles Manson from a standpoint of ethical absolutes. Well, what of it? I don’t need to live in a world where Hitler was wrong because the universe tells me so — I feel that he was wrong myself, and fortunately many other people agree with me. So I and these other like-minded people sit down to work out among ourselves what rules we want to live by, and we decide that people like Hitler are bad and should be stopped. The codification of moral rules does not come from examining the world or thinking about logical necessities; it comes from individual human beings examining their own desires, and communicating with other human beings to formulate rules of common consent. Some people might prefer that moral rules have a more timeless, universal standing; but personal preference does not affect the working of the actual universe.

Gay marriage is a excellent example of a rule that would be almost universally agreed upon by individual human beings negotiating in good faith, and it is to our culture’s endless embarrassment that at this late stage we are still struggling to get it right. Deep down, there are only two arguments against gay marriage. One, which is the one that actually drives most people’s views on the matter, is that it’s icky. They just don’t like the idea, and therefore don’t want it to exist. There is little point arguing against that, but we can hope that increasing normalization of the idea of homosexuality will cause such attitudes to become increasingly rare.

The other argument is that gay marriage is a violation of Natural Law. That the two human sexes clearly belong together (“Adam and Eve, not Adam and Steve”) and the institution of marriage is a sacred covenant between a man and a woman. But once we understand how the universe works, in our post-Enlightenment era, there is no reason to take arguments like this seriously. Nature doesn’t have anything to say about the moral status of two individuals falling in love and formalizing their relationship. It is a matter for us individual human beings to get together and decide how we should structure our legal system. We have long ago decided to recognize the special legal status of two people who love each other and wish to formalize their status as a legal union. Marriage is a wholly invented institution; there is nothing “natural” about it. And there is simply no reason — ickiness aside — to limit that institution to heterosexual couples. There might be, if the existence of gay married couples had directly deleterious effects on other members of society; but it doesn’t, crazy exhortations about the looming threat to traditional families notwithstanding.

Opponents of gay marriage are either squeamish and prejudiced, or philosophically confused. Eliminating prejudice takes time, but the situation is gradually improving. But there is even less excuse for the philosophical confusion surrounding issues like this. And if it takes a Physics Blog to sort things out, we’re happy to take up the challenge.