Here’s a kernel for some thinking about how we treat evidence:

“The Case That Never Dies”, by Dorothy Rabinowitz in the Wall Street Journal.

You may guess from her article’s title that Rabinowitz does not think highly of the fifty-year controversy about who killed Kennedy. A detectable attitude of condescension rises from the phrase, the case that never dies. By the end of her article, she comes out with it: she says the people who propose one scenario in particular about Kennedy’s death are deranged.

I don’t think the scenario – that a Secret Service agent behind Kennedy’s limousine accidentally shot the president from fairly close range – fits the evidence we have all that well. Nevertheless, the dismissive mode always bothers me. Rabinowitz’s language in the Journal article is relatively sophisticated, but the result is the same: dismiss people who don’t see things the same way you do as deranged, which is another word for crazy.

It happens so much, you wonder if the people who do it even know how to evaluate evidence. They’ll respond that the evidence presented is beneath consideration. We won’t, they say, waste our time with stories that Kennedy arranged his own assassination. Similarly, we won’t waste our time with the idea that Oswald was patsy, if the government’s case against him is so comprehensive and convincing.

The attitude toward alternate scenarios from the Oswald-did-it group is, give me a break. I don’t want to deal with nutcakes. To be honest, the reaction of many who are skeptical of the Warren report is not so different. They look at the contents of the commission’s report and think similarly: give me a break. I don’t want to waste my time with government flunkies. Consequently, the two sides of this argument don’t engage with each other.

The great thing about a courtroom is that the two sides do engage with each other. The entire process and structure for presentation of evidence and cross-examination is designed for that. The free flow of conversation on the Internet points the other way. All the currents go toward playing to the people who already agree with you. Why try to convince people who will never agree with you anyway?

In light of that, it’s not surprising both sides have the same reaction to evidence on the other side: how can anyone believe this stuff? One problem for assassination skeptics is that they are generally more fragmented than the people who place their confidence in the Warren commission. When the skeptics argue with each other, and denigrate possibilities they don’t like, the people who accept the Warren report look stronger by comparison. “We don’t argue,” the Oswald-did-it group implies, “because we’re right.”

We can see a similar phenomenon in the way we deal with evidence about the 9/11 attacks. Here’s a quick example. Judy Wood wrote a book called Where Did the Towers Go? She presents a lot of evidence that a directed energy weapon destroyed the Twin Towers. The book is not a weird pamphlet about how aliens came to our planet with advanced laser beams to destroy big buildings and kill people. Wood collects a lot of different kinds of evidence, and presents it thoroughly. Scientists would say this evidence calls for evaluation. No scientist would say it is beneath consideration. Before long, scientists who dismiss evidence without looking at it find themselves mistaken.

What do we find in an online discussion of various scenarios about 9/11, including Wood’s thesis? We find someone who says, essentially, “Here’s a good one: Judy Wood has written a book that says the Twin Towers were destroyed by weapons in SPAAAAAAAACE!!” That’s it. The writer doesn’t not feel any need to say more than that. Just ridicule the other person, and expect that people will join you. These are playground rules: make fun of the odd one out, and you’ll find plenty of people who want to join you. They know that if they don’t join in, or at least keep quiet, they could be the next object of scorn.

Playground rules and science are not the same. Playground rules and forensics are not the same. Scientific reasoning and careful evaluation of forensic evidence are all we have to find the truth. Public ridicule won’t do it. Calling people deranged won’t do it. Dismissing evidence as beneath consideration won’t do it. We have a lot of proven methods to discover true knowledge. Those methods vary depending on the type of evidence available. Every method has this much in common: you can’t reach reliable conclusions if you don’t look at the evidence at all, or if you look at only part of it.

Yes, we do have to decide what counts as evidence and what does not, but you cannot make a decision like that without considering each candidate puzzle piece for at least a short period of time. Dismissing something out of hand as crazy indicates you have not considered it at all. To sort evidence from non-evidence, you have to look at everything that could possibly be relevant, not just items consistent with what you already believe. To sort evidence from non-evidence, you have to think, not ridicule.