The Logic of the Moon Hoax Argument

The Hoax Theory Claims:
The evidence supporting the moon hoax theory is based on scientific study and logical conclusions.

Logic is somewhat like mathematics. It is a field of study which uses standardised principles and formulae to maintain a consistent and reliable approach to answering questions. When used correctly, the worth of logic has been proven — logical methods work. Very few people, including hoax theorists and debunkers alike, would dispute this.

Unfortunately logic is often misunderstood or used incorrectly. In the same way that tricks can be played with mathematics to produce seemingly impossible answers, logic can provide false conclusions when the rules are bent.

Since hoax theorists maintain that their theories are founded in logic, they must show that their implementation of the rules of logic are sound. If the logic is flawed then there is no basis for the theory. Strictly speaking, the entire theory could be summarily dismissed if the underlying logic does not hold up.

Ironically, hoax theorists often use the word logic in their arguments without actually implementing any logic at all. Here's a typical statement from a hoax believer:

"Think about it logically — the Russians were ahead of the Americans for most of the space race but they pulled out and never made it to the Moon. They must have known it was impossible".

I defy anyone to show me any principle of logic which supports this statement. And that's the crux — you can't just say your argument is logical without showing exactly how your logic works. "Common sense" isn't good enough, you actually have to demonstrate the logical process you used to reach your conclusion. If you can't, then using the word "logic" is meaningless.

Let's have a closer look at some relevant principles of logic...

Logical Deduction

The hoax theory frequently calls on the maxim "When you have eliminated the impossible, whatever remains, however improbable, must be the truth." This popular rule of logic is often used in fictional detective works, most notably Sherlock Holmes. For the sake of simplicity we'll call it the "Holmes Rule".

An example of the Holmes Rule in use is the "identical photos" argument, where two photos of different locations on the moon appear to have identical backgrounds. The theory claims that there is no possible way this could have happened on the moon, so the improbable scenario of a hoax must therefore be true.

This logic fails because:

  1. The theory makes no realistic effort to find or eliminate all other possible explanations.
  2. Even if other explanations could be eliminated, there is no logical process which leaves a hoax as the only remaining possibility.

The underlying problem is actually the use of the Holmes Rule at all. Although it sounds very logical, this maxim is only useful in a limited number of situations; specifically, when you can be 100% aware of all possible explanations. If you cannot be completely sure you have identified each and every single possible answer, how can you rule them all out and leave a single correct answer?

In fact, the Holmes Rule is only suitable for "black and white" questions such as mathematics. When investigating things like the moon hoax it is not the correct use of logic. Rather than eliminating explanations and trying to leave a single one, the correct approach is to list as many explanations as possible and identify the one which is most probably correct.

The Principle of Parsimony

Parsimony means "Adoption of the simplest assumption in the formulation of a theory or in the interpretation of data".

This principle is is very important in logic. It is a way of narrowing down several possible answers to a particular question and determining which one is most likely to be correct. Basically it states that the simplest answer is most likely to be the correct answer. More specifically, the explanation which makes the least number of unproven assumptions is most likely to be the correct answer.

Note that this principle does not prove anything - rather, it is used to determine the correct probabilities.

If we apply this principle to the "identical photos" question we can suggest two possible explanations (although there may be others as well):

  1. The photos were mixed up or mislabeled by NASA in a simple clerical error.
  2. The entire moon landing was a hoax.

Since we know that clerical errors do happen at large organisations such as NASA, the first explanation is simple and requires no new assumptions. However the second scenario requires us to accept a complex solution with many assumptions. Therefore the principle of parsimony requires us to take the first explanation as the most likely correct answer. However the hoax theory states that the second explanation is the most likely - for no reason other than they say so. This is a blatant disregard for one of the most fundamental principles of logic.

This theme is common in moon hoax claims. Time and time again, things which could have many simple explanations are instead taken as proof of a single, far more complex explanation.

The Burden of Proof

Whose responsibility is it to prove that the moon landings were real? There is a widely-held belief that it is NASA's responsibility to prove the conspiracy theorists wrong in order to prove the moon landings were real.

There is a principle which states: The person proposing a theory has the burden of proof.

To paraphrase a common catch cry of hoax theory supporters: "Despite the evidence, we don't believe the landings were real. We have proposed our own theory. Unless you prove that we are wrong then we must be right."

Logic dictates that this is not the case. You cannot assume you are right just because someone else has failed to prove you are wrong.


Many arguments (on both sides of the debate) contain logical errors. An error in logic is just like a mathematical equation which puts expressions in the wrong order - the answer won't be right if the process isn't right. It goes like this:

Invalid Evidence + Valid Logic = Invalid Conclusion
Valid Evidence + Invalid Logic = Invalid Conclusion
Valid Evidence + Valid Logic = Valid Conclusion

When evaluating a theory, don't just ask if the conclusion makes sense based on the evidence provided. Ask whether the logical process has been correctly followed. After all, the hoax theorists themselves have based their cases on this process.

Next Page: Credentials of Those Proposing Evidence