See? People Do Declare to Be True That Which Can Easily Be Proven False!

I mentioned yesterday that "People lie all the time, quite convincingly, even when they know they could easily be caught in the lie." And even if we don't think are lying, necessarily, people can quite easily spread falsehoods and misinformation.

Exhibit A, Penn Jillette:

Yesterday, around 3 p.m., a trend started emerging on Twitter. People began reciting a quote from Martin Luther King Jr. that seemed strangely apt for this occasion:

"I mourn the loss of thousands of precious lives, but I will not rejoice in the death of one, not even an enemy."

The first person to cite it on Twitter was the famous magician/Libertarian Penn Jillette, but the words quickly went viral, and the source got lost in the shuffle. The only problem? As Megan McArdle pointed out in the Atlantic, Martin Luther King never said that. Actually, the quote from MLK about enemies is:

"In the End, we will remember not the words of our enemies, but the silence of our friends."

How did this other quote get misattributed to King? As McArdle says in her piece, "It's a bit too a propos. What 'thousands' would King have been talking about? In which enemy's death was he supposed to be rejoicing?" She also wonders, "Why? What do you get out of saying something pithy, and getting no credit for it?"

Penn admits to being the originator of the quote on Twitter, though he claims it got messed up when he cut and pasted from a longer piece by King. I'm not sure if I believe him; I have a strong suspicion Penn just made it up in order to see how many people would blindly follow along and quote it as fact, without ever checking on the sources. After all, this is the guy who created the documentary "Penn and Teller: Bullshit!" and the subsequent Showtime series about how easy it was to dupe people.

Update: The source of the quote is a Facebook message by Jessica Dovey, where she goes on to quote Martin Luther King Jr. In this context, it's easy to see how a cut-and-paste job could have accidentally attributed the source to King. Congrats to Jessica, whose Facebook wall post is one of the more famous sayings on the Internet today. Salon has reached out to Penn Jillette for comment, but has yet to receive a response.

The lesson? A claim should not be considered true just because it could easily be proven false. If you don't do the work of actually researching and see if it is false, you may be misled.