Alan Dershowitz on Being Wrong

Kathryn Schulz, author of Being Wrong: Adventures in the Margin of Error, interviewed Alan Dershowitz in Slate.

I want to ask you about the function of error within the law.
I think mistakes are the essence of science and law. It's impossible to conceive of either scientific progress or legal progress without understanding the important role of being wrong and of mistakes. Both [science and the law] are built on learning from mistakes.

It's an interesting analogy, but there are some salient differences between science and the law. If you think of them as two different systems to arrive at some kind of truth—
No, I don't agree with that. I don't think the law exists to arrive at the truth. If it did, we wouldn't have exclusionary rules, we wouldn't have presumptions of innocence, we wouldn't have proof beyond reasonable doubt. There's an enormous difference between the role of truth in law and the role of truth in science. In law, truth is one among many goals.

Sure, but aren't those examples you cite partly protections we built into the law out of respect for how hard it is to get at the truth? Take reasonable doubt: Ever since Maimonides, legal theorists have argued that it's better to let a hundred guilty people go free than to convict one innocent person. That seems like embedding awareness of fallibility, of our imperfect access to the truth, within the institution of the law.

The law is agnostic about truth. It's very skeptical of ultimate truth. That's why freedom of speech permits lies to be told. Most liberal democracies don't try to figure out what the truth is. I would be very upset if my country, like Hobbes, decided there was truth. Hobbes said that one of the obligations of those who govern is to censor lies, because those who govern have unique access to the truth. That's not the American way.

Right. I think we're making the same point. The American political and judicial system is founded in acceptance of the notion that we are liable to err—in contrast to, say, monarchies, where rulers were taken to be infallible.

I had an opportunity to discuss this once with [Richard] Feynman, the man who won the Nobel prize in physics. What I say about law he says about science: that with very, very rare exceptions, there aren't ultimate unchangeable truths and that a brilliant mistake is the most important contribution a scientist can make. For example, phrenology,  which was just totally wrong, contributed an important thing to science, because it was really the first pseudo-science that said there's a connection between the mind and the brain. Phrenologists got everything wrong, but they were right that in some ways the brain determines the content of the mind. So that was a grand mistake, a great mistake. Neuropsychology and neurobiology-almost all the neurosciences emerged from the great mistake of phrenology.

So what's the analogy in the law?
What is the common law? The common law is a statement that says that we never quite get it right. Every lawsuit results from somebody doing something wrong. If everybody did right, we wouldn't need laws. It's mistakes, some accidental, some deliberate, that drive the law to constantly adapt and change. So I think it's crucially important that we look at errors and learn from them and adapt to them.

I wrote a book called Rights from Wrongs, and the whole point of the book, which is my whole philosophy of life, is that we learn so much from our mistakes. Our rights come from all the wrongs we've done. The 13th, 14th, and 15th amendments grew out of recognition of the horrors of slavery. The entire human-rights agenda internationally grew out of the Holocaust. I wrote another book [The Genesis of Justice] about how the Book of Exodus, which has the Ten Commandments and all the rules, grows out of the terrible mistakes that characters make in the Book of Genesis. My whole philosophy is based on correcting error, trial and error. Or, rather, error and trial.

Can you give me a contemporary example?
I'll give you a perfect example. So Goldman Sachs does something terrible. They get a man who was betting against certain bonds to pick the bonds for a fund that's betting in favor of those bonds. There's one problem: Although we know it's terrible and it doesn't pass the smell test, it happens not to be against the existing law, because it's such a clever technique that no one else thought of it. You can't anticipate all possible mistakes or evildoing that people can come up with. So in the end we may have to give Goldman Sachs a pass on this one and use their terrible mistakes as a basis for passing new legislation. And then people like [hedge-fund manager John] Paulson will figure out ways of evading the new legislation, because the bad guys are always a step ahead of the good guys. They're always cleverer; they have a greater motivation.