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July 18th, 2019 (Permalink)

The Second Draft of History

The recent theme of this weblog has been fact-checking or, more precisely, the lack of it. Of course, mistakes will happen, but some recent ones are egregious errors that can only happen because those who commit them fail to make even a minimal effort to check them. Here's a recent example from the beginning of a newspaper article on the fiftieth anniversary of the launch of Apollo 11 to the moon:

A few days before the historic walk on the moon, Apollo 11 took off from the earth―50 years ago on July 16. Four days later John Glenn would step onto the only other planet we have ever walked on, and uttered the famous words "on [sic] small step for a man, one giant step for mankind."1

Putting aside the grammatical and spelling errors, there are three mistakes in the second of these two sentences2:

  1. John Glenn never walked on the moon.
  2. The moon is not a planet. Sadly, no human being has ever walked on another planet.
  3. It was Neil Armstrong who spoke the words: "That's one small step for [a] man, one giant leap for mankind."3

First of all, it surprises me that anyone would not know the first two of these facts. Secondly, even more surprising is that a newspaper would publish this without someone catching and correcting the errors. A quick visit to NASA's page on the mission4 would be enough to correct the first and third errors. The second is an elementary error in astronomy, and could be corrected by consulting a dictionary of astronomy, but you could also just type the question: "Is the moon a planet?" into Bing, and it would helpfully inform you otherwise5.

Of course, none of this will help any if you don't do it. The primary problem is not that it would take lengthy research to discover these facts, since doing so should take no more than five minutes. Nor is the main problem even factual ignorance, though that is indeed a concern. Rather, the crux is ignorance about ignorance―meta-ignorance, if you will: the illusion of knowledge that led the author and editors to not have bothered to spend those five minutes checking.

An old journalism saying is: "If your mother says she loves you, check it out." In other words, even if you're convinced you already know something, check it anyway. Don't trust anyone, least of all yourself! As Richard Feynman said: "The first principle is that you must not fool yourself―and you are the easiest person to fool.6"

There's another old journalistic saying that news is "the first, rough draft of history"7, but the launch of Apollo 11 was half a century ago so this is at least the second, even rougher, draft. At this rate, in another fifty years it will be Yuri Gagarin who was the first man to set foot on the moon.


  1. Alex Griswold, "New York Daily News Reports That 'John Glenn' Was First Man on 'Planet' Moon", The Washington Free Beacon, 7/16/2019. The following is the corrected version of the original article: Theresa Braine, "Relive humanity’s journey to the moon, starting with the 50th anniversary of Apollo 11 launch day", New York Daily News, 7/16/2019. The original, uncorrected version of the story seems to have been removed without notice by the Daily News, but there was also a Facebook post publicizing the article which contained its first two sentences. That post, too, has disappeared from Facebook, but Google still has a cache of it; see: "New York Daily News", Facebook, 7/16/2019. It's understandable that the Daily News is embarrassed by these mistakes, but concealing them in this way risks removing an incentive to get things right, namely, reputational damage. For this reason, the newspaper should also be embarrassed for sweeping this under the rug.
  2. It would be a hasty generalization to conclude based on this one instance that the New York Daily News averages one-and-a-half mistakes per sentence on all of its stories. However, this may answer negatively the question whether newspapers do any fact-checking.
  3. Armstrong intended to say: “That's one small step for a man, one giant leap for mankind”, but a lot of people―myself included―didn't hear the "a", and it is still sometimes given without it. However, without the "a" the sentence doesn't make any sense, since "man" and "mankind" both refer to the human species. So, Armstrong would have been saying that the first human step onto the moon was both a small step and a giant leap, which is impossible. What Armstrong meant was that this was a small step for himself―"a man"―but a giant leap for humanity. See: "Armstrong’s famous “one small step” quote―explained", The Associated Press, 7/13/2019.
  4. Sarah Loff, "Apollo 11 Mission Overview", NASA, 5/15/2019.
  5. I'll leave it to you to check this for yourself.
  6. Richard P. Feynman, "Cargo Cult Science", Caltech, 1974. Feynman, of course, was talking about science, but the principle applies to any attempt to find out something about the world.
  7. This saying is often attributed to publisher Philip Graham, but versions of it appear to have been around before Graham popularized it. See: Jack Shafer, "Who Said It First?", Slate, 8/30/2010.

July 7th, 2019 (Permalink)

Rule of Argumentation 61: Defend your position!

This is how arguments usually start: someone makes an affirmative claim that someone else either denies or at least doubts and challenges. If you are the person making a claim and someone challenges it, the burden is on you to defend that claim. If you cannot or do not wish to defend it, then you should withdraw it2.

You may be familiar with the notion of burden of proof in the Anglo-American legal system. In a criminal case, the burden of proof is on the prosecution to prove the defendant's guilt beyond a reasonable doubt. At the very least, the prosecutor must present a prima facie3 case for guilt. If the prosecution succeeds in presenting a prima facie case then the burden of proof switches from the prosecution to the defense. However, if the prosecutor fails to present such a case then the defense wins, that is, the defendant need not even present a case unless the prosecution meets its burden of proof.

Another way of making this same point is that in the Anglo-American legal tradition there is a presumption of innocence, that is, the defendant is presumed innocent until proven guilty. The presumption of innocence is the other side of the burden of proof coin: the burden is on the prosecution and the presumption is in favor of the defendant. If the prosecutor meets the burden with a prima facie case, then the burden and presumption switch: the burden is then on the defense to rebut the prosecution's case sufficiently to show a reasonable doubt of the defendant's guilt.

The notions of burden of proof, presumption, prima facie evidence, and the shifting of the burden of proof can all be extended from the legal realm to argumentation in general. However, it's not obvious who gets the burden and who gets the presumption, that is, who plays the role of the prosecutor and who the defendant?

The answer is that the burden is on the affirmative rather than the negative, that is, on he who affirms as opposed to she who denies. The reason for this is an asymmetry between affirmative claims and denials, namely, that it is much easier to find evidence for an affirmation than a negation4. Moreover, unless they just blurt out claims for no reason, those who introduce a claim should be able to produce some evidence to support it. In contrast, you may be skeptical of a claim without having studied or considered the matter enough to present evidence against it.

The burden of proof is not all or nothing, but comes in degrees. If you assert a plausible claim then the burden of proof will be light, whereas an implausible claim places a heavy burden on you. This is the basis for the familiar saying that extraordinary claims require extraordinary evidence5.

Logical fallacies that result from attempts to evade the burden of proof include6:

So, the burden of this rule is that if you make an affirmative claim, be prepared to defend it. If, in contrast, you are the challenger and the proponent of the challenged claim makes a prima facie case, then accept the burden of proof. It is now up to you to either make a case against the claim, or to accept it.

Next Month: Rule 7


  1. Previous entries in this series:
    1. Rule of Argumentation 1: Appeal to reason!, 12/14/2018.
    2. Rule of Argumentation 2: Be ready to be wrong!, 1/26/2019.
    3. Rule of Argumentation 3: Focus on claims and arguments!, 2/13/2019.
    4. Rule of Argumentation 4: Be as definite as possible!, 3/8/2019.
    5. Rule of Argumentation 5: Be as precise as necessary!, 5/29/2019.
  2. As with all the rules discussed in this series, this is a rule of thumb, that is, a rule that has exceptions. For this rule, common sense is an exception. For instance, a person who asserts that every living thing eventually dies does not bear the burden. Instead, those who challenge such a claim must make a prima facie case against it, and only then does the burden shift to the claimant.
  3. Latin for "at first sight". See: Eugene Ehrlich, Amo, Amas, Amat and More: How to Use Latin to Your Own Advantage and to the Astonishment of Others (1985). A prima facie case for a claim is one that is sufficiently strong to prove the claim unless successfully rebutted.
  4. It is often said that you can't prove a negative, which is over-stated but a good rule of thumb. For an explanation of how much truth there is in this saying, see: Logical Literacy: "You can't prove a negative.", 3/14/2015.
  5. Popularized by the astronomer Carl Sagan, see: Broca's Brain: Reflections on the Romance of Science (1980), p. 73.
  6. For more on each fallacy, see the entries under the names of the fallacies available from the drop-down menu in the navigation pane to your left.

July 4th, 2019 (Permalink)

An Independence Day Puzzle at the Logicians' Club

In July of 2019, the Logicians' Club* held its monthly meeting on the fourth. To celebrate the holiday, the members played a game. On this day, its three regular members were in attendance: Mrs. A, Miss B, and Mr. C. It was the latter who suggested the game and organized it for the other two members to play. They met in a private room of the tavern where the club meetings were held.

"Fellow logicians," Mr. C began impressively after clearing his throat, "I have here a bag of patriotic hats," he said, holding up a large opaque bag. "Two of the hats are red, two are blue, but only one is white." He reached into the bag, pulled out a white hat and placed it on his own head.

"In a few minutes," he continued, "I will turn out the lights and pull two hats out of the bag. Then I will place a hat on each of your heads. When I turn the light back on, both of you will be able to see the color of the other's hat, but you won't be able to see your own. I will ask each of you to guess the color of your own hat by whispering in my ear so that the other player won't know your guess. If at least one of you is right, you will both win a prize which you can share.

"Now, I'm going to step out of the room for a few minutes and allow you time to confer. It won't be cheating if you agree between you on a strategy for playing the game. Remember two things: first, only one of you has to guess the color of her hat correctly in order to win the prize―it doesn't matter whether the other player's guess is incorrect; second, if you win you will share the prize, so this is not a competitive game. Good luck!" And he left the room.

Is there a strategy that the two logicians can use to ensure that they win the prize? If so, what is that strategy?

* For other meetings of the club, see:

(Added 7/9/2019) An anonymous reader wrote in wondering whether Mr. C could have taken the white hat that he put on his own head and put it on one of the two players when the lights were out. Of course, he could have, but rest assured that he didn't.

(Added 7/5/2019) Thanks to Lawrence Mayes for pointing out a loophole in the description of the game which has now been closed by amending this sentence.

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