Rules of Logic and Probability

Thinking About Conspiracy

The Kennedy assassination is nothing if not a huge intellectual puzzle. Anybody who wants to solve that puzzle would be well-advised to use the intellectual tools that have been tried and proven. Unfortunately, conspiracy books often ignore basic rules of logic and build an edifice of speculation. Yet they can be quite convincing.

Just how do they convince their readers? And how would sound intellectual inquiry proceed?

Wildly Improbable Coincidences?

Conspiracy books regale their readers with "coincidences" that, the authors imply, could not really be coincidences at all, but must be the result of some sinister machinations. Are the "improbable coincidences" that are supposed to be sinister really so improbable and do they really suggest something sinister?

Too Many Mistaken Witnesses?

Conspiracy books specialize in marshalling eyewitness testimony that supports conspiracy theories. They parade past readers witnesses who thought the shots in Dealey Plaza came from the Grassy Knoll. They discuss witnesses who saw Lee Oswald in the company of supposedly sinister people like David Ferrie or David Atlee Phillips. They recount the testimony of witnesses like Roger Craig who told of all kinds of sinister events in Dealey Plaza in the wake of the assassination. They can produce a lot of witnesses like this.

The conspiracy books then ask, rhetorically, "could all of these witnesses have been wrong?"

Just how many witnesses would one expect to be wrong in a very large and very complicated case like this one?

All Those Sinister Connections?

Conspiracy books specialize in tracing "connections" between people and groups. They can connect just about everybody they think to be sinister to just about everybody else that they consider sinister. Just how many "connections" would we be able to find if nothing at all sinister was going on among all these people? Do the "connections" that conspiracists have uncovered suggest conspiracy, or just the normal operation of the laws of probability?

How Big a Conspiracy?

Conspiracists seem to like big conspiracies. Such conspiracies allow the theorist to explain away all the evidence against Lee Oswald. After all, all the witnesses and investigators who produced such evidence can be branded liars. And big conspiracies are satisfying because they can include all the groups one happens to dislike.

But do these theories pass muster as sound historical logic?

Opinions Are Not Evidence

Conspiracy books often quote people with high positions in the U.S. government, right up to and including President Johnson, who believed there was a conspiracy. Surely these people are "in the know," and if they believe in a conspiracy there must have been one, right?

What Scenario Does the Evidence Imply?

In sorting through a huge mass of documents and testimony, the honest researcher is constantly faced with questions like "is this witness telling the truth?" and "does this incident suggest something sinister going on?" To evaluate the evidence, one has to ask some critical questions, like "if this witness is telling the truth, what does it mean?" and "if this incident is really sinister, what does it imply?"

In other words: think scenario.

Quite often, witness testimony can be discarded simply because, if what the witness says is true, it implies some absurd theory of how conspirators acted. Double Trouble: conspiracists positing two of everything

Double Trouble

One should try to make one's theories fit the data, and one should try to fit all the data, without selectively ignoring inconvenient things. But it's also the case that one should not concoct a more elaborate theory to fit data that are erroneous. What happens when one produces a theory to explain witnesses who happen to be mistaken, documents that contain errors, and things you just think you see in photographs? You end up with two of everything.

The Truth is in the Documents?

Conspiracists are convinced that the truth is not merely "out there," they are convinced it's in the documents — the massive body of testimony, reports, letters, memoranda and so on that both government agencies and private investigators have built up over 40 years.

But if one can find a lot of truth in the documents, one can find a huge amount of falsehood too. How does one sort out the truth and the mistakes, lies, errors, distortions and just plain wacky stuff? Very few people have looked at more documents than veteran researcher Paul Hoch. In 1993 he spoke at the Second Annual Midwest Symposium on Assassination Politics in Chicago and shared what nearly three decades of experience had taught him about reading the primary sources.

Dr. James Fetzer: conspiracist philosopher

Jim Fetzer: Getting it All Wrong

The fellow at right is Prof. James Fetzer, Distinguished McKnight University Professor at the University of Minnesota, Duluth. Notwithstanding the fact that the Duluth campus should not be confused with the Tier 1 research university in Minneapolis, this is still a quite respectable academic credential. But where conspiracies are concerned, Fetzer has some rather odd beliefs.

For example, he recently appeared on "Black Op Radio" to discuss the assassination and related topics. The following URL will take you to his interview.

At about 10:00 into the clip, you can hear Fetzer say that there is an "awful lot of evidence that throws the whole moon landing scenario into doubt." That's right, Fetzer thinks whether NASA landed men on the moon is an open question. The problem with such theories is obvious, as Fox News columnist Rand Simberg has pointed out:

Of course, the hardest part of the theory to buy is that NASA, an organization of thousands of people in a position to know, and its contractors, were all paid off, or threatened into never talking about how the lunar landings were staged. If NASA could actually pull that off, it would be a greater achievement than landing people on the moon. This would be one of the biggest stories of the century, but we're asked to believe that in a government that leaks to the press like a shotgunned sieve, not only is no one talking, but also that all of the astronauts are lying as well. None of them will break ranks.
Yet Fetzer touts the "evidence" for a moon landing hoax apparently without even thinking about this problem.

How Many Shooters in Dealey Plaza

While lone assassin theorists think there was one shooter in Dealey Plaza, and conspiracists usually up that number to two or three, Fetzer outdoes them all. At about 15:40 in the clip above, he explains that:
. . . we actually know that eight, nine, or ten shots were fired in Dealey Plaza from what appear to have been six different locations.
How do we "know" this? In Murder in Dealey Plaza Fetzer quotes a photoanalyst in the CIA's National Photographic Interpretation Center who saw the Zapruder film several times on the weekend of the assassination. According to Fetzer, he "reported that . . . he had concluded that JFK was hit 6 or 8 times from at least three directions" (p. 10). How Fetzer upped the ante to eight or ten shots from six locations is unclear, but he appears to have outdone even Jim Garrison, whose scenario eventually included shots from five locations.

How any conspiracy would expect that it could have shooters at six different locations and not have a least one in a location other than the Depository discovered is something Fetzer doesn't bother to explain.

Terrorist Attacks

Fetzer doesn't do any better when he talks about the 9/11 terrorist attacks. He doesn't believe that American Airlines Flight 77, a Boeing 757, actually hit the Pentagon! Rather, a cruise missle did. Fetzer discusses this issue at about 17:00 into the audio clip above. He even has an entire page of links to support his view.

What actually happened to Flight 77 is something Fetzer doesn't explain. And how there just happened to be five passengers aboard who had terrorist links is also something he doesn't bother to explain, although one wouldn't be suprised if he claimed that those links were all trumped up. As in the moon landing case, Fetzer doesn't seem deterred by the sheer number of people who would have to be involved in a "Pentagon attack" conspiracy. He seems to somehow believe that the government can keep any number quiet.

What about his views on the Kennedy assassination? He's a conspiracist, of course, and endorses the notion that the Zapruder film was somehow faked, forged, or tampered with. What of all the evidence against Oswald? In his book Murder in Dealey Plaza he dismisses it by claiming:

A research group . . . has discovered that JFK autopsy X-rays have been fabricated, autopsy photographs have been distorted or destroyed, the brain seen in official diagrams and photographs belonged to someone other than JFK, the autopsy report was a sham, and a great deal of the photographic record, including the Zapruder film of the assassination, has been edited by means of sophisticated techniques (p. ix).
Just who all had a role in this massive plot? Fetzer is not shy about naming names.
The fabrication of the X-rays, the substitution of someone else's brain, revision of the autopsy, photographic fakery, and the destruction and alteration of other crucial evidence — including the Presidential Lincoln limousine . . . was carried out by specific individuals who have specific names, including the autopsy physicians, James J. Humes and J. Thorton Boswell; John Ebersole, the officer in charge of radiology; Secret Service agents Roy Kellerman and William Greer, who were in charge of the limousine at the time of the assassination; and the President's personal physician, Admiral George G. Burkley, among others; but also unwitting employees of other governmental agencies, including two at the National Photographic Interpretation Center (NPIC), Homer McMahon and Bennett Hunter, who had a film of the crime in their hands the weekend it occurred.

Others at the Pentagon, the CIA, and the FBI may bear greater or lesser degrees of responsibility for the alteration and destruction of evidence. . . . Others, whose specific names and specific roles are explained and explored in various of the studies that follow, however, obviously assumed leading roles in managing the evidence whose alteration and destruction was ingeniously contrived. If one where to ask why officers of the Navy, agents of the Secret Service, and other persons associated with the FBI and the CIA should have assumed such roles, the answer is all too obvious (p. x).

Saying something is "obvious" is a handy way to avoid explaining it, and especially handy if your explanation wouldn't sound too convincing.

Fetzer then sums up by asserting that all his claims have been solidly proven.

The complicity of medical officers of the United States Navy, agents of the Secret Service, the President's personal physician, and other representatives of the Pentagon, the FBI, and the CIA provides powerful evidence that can serve as a premise in the appraisal of alternative theories about the assassination of JFK (p. 13).
The fact that Fetzer has to posit such a huge conspiracy to suppress, forge and tamper with evidence is an implicit admission that the case against Oswald is massive. If the Zapruder film shows the back of Kennedy's head intact (while conspiracists insist that the back was blown out, indicating a shot from the Grassy Knoll), it must have been tampered with. If the limousine showed only bullet strikes from behind . . . well, it must have been hit from the front too or they wouldn't have renovated it. If the autopsy photos and X-rays show Kennedy was hit twice from behind, well then of course they were forged also.

Any theory must reject some evidence. Lone assassin theorists, for example, reject the testimony of many witnesses as "mistaken." The question is: how plausible is a particular refusal to accept evidence? Where witnesses are concerned, the scientific evidence shows that their testimony is unreliable. Further, lone assassin theorists often reject particular witnesses when they find the majority of witnesses on the other side of the issue — as is the case of the "earwitnesses" in Dealey Plaza. In other cases, they reject witness testimony when it contradicts photographic evidence — as in the case of the claim that a Mauser and not Oswald's rifle was found on the sixth floor of the Depository, or the claim that the back of Kennedy's head was blown out.

But just how plausible is it to believe that a conspiracy the size of Fetzer's could function successfully and keep its work secret for four decades? Americans should ask themselves, "is our government really that competent, and if so, why haven't we noticed before now?"

Return to Kennedy Assassination Home Page