In a seminal episode of the sitcom Seinfeld, Jerry Seinfeld turns to his mendacious friend George Costanza for advice on how to beat a lie detector test. After first comparing the request to asking famed Italian opera star Luciano Pavarotti how to sing like him, George replies, “Jerry, just remember. It's not a lie ... if you believe it.”

Journalists have an understandable hesitance toward using the blunt word “lie” to describe the statements of politicians. But at some news outlets, this hesitance has drifted into acceptance of the George Costanza Rule of Lying: a statement cannot be termed a “lie” unless there is demonstrable evidence that the speaker truly believes it to be false. Since reporters can’t read minds, it is virtually impossible to meet this standard.

White House press secretary Sean Spicer sought to exploit this vulnerability in Monday’s press conference. After he offered a series of obviously false and easily disprovable statements on Saturday about the crowd size at President Trump’s inaugural festivities, many journalists abandoned their typical hesitance and branded his statements as “lies.”

Spicer doesn't want reporters calling him a liar because that would make it impossible to do his job. And he definitely wants to ensure that they don't use that terminology to refer to President Trump. So he used his first press briefing to claim that his statements aren’t lies if he believes them.

Asked by ABC’s Jonathan Karl whether it is “your intention to always tell the truth from that podium, and will you pledge never to knowingly say something that is nonfactual,” Spicer responded that his “intention is never to lie,” but at times he will unknowingly pass along incomplete or inaccurate information. He explicitly compared this to the mistakes that journalists make, saying that while sometimes news outlets have to publish corrections, “that doesn't mean that you were intentionally trying to deceive readers and the American people” and thus it would be unfair to “turn around and say, ‘OK, you were intentionally lying.’”

Spicer’s statement had two aims. First, he was trying to establish the circumstances under which it would be appropriate for journalists to accuse him and others in the Trump administration of lying. Rather than journalists making that assessment based on context -- whether the false statement has been repeated after being disproven, or whether it is so false on its face that it defies other explanations -- he wants them to reserve the term for cases where they can prove the speaker doesn’t believe their words. This is a standard so high as to be virtually impossible to meet.

Second, he appealed to journalists’ sense of fairness by suggesting that his errors and those of journalists are similar, and thus it would be wrong to hold him to a different standard, since surely they wouldn’t want to be accused of “lying” every time they misreport a story.

Neither prong of this argument stands up to scrutiny.

Trump and his ilk make false statements with such frequency, brazenness, and repetition that the best way to characterize what's happening is to say they are lying. You don't need a mind-reading device to know that if someone is repeating a false statement over and over again after it's been pointed out that it's inaccurate, they are doing it deliberately and thus lying.

The sheer volume of falsehoods that Spicer crammed into his Saturday statement -- at least four blatant ones and a fifth misrepresentation, all in service of his claim that “This was the largest audience to ever witness an inauguration -- period -- both in person and around the globe” -- should convince journalists that he doesn’t deserve their trust.

Likewise, Trump’s habitual lying, at a rate far beyond what is typical for politicians, suggests that journalists should not assume that he is acting in good faith, but rather that he is trying to deceive them. News outlets that refuse to suggest that the president is lying under those circumstances are doing their audiences a disservice.

The good news is that some outlets have been willing to cross that bridge and acknowledge when the president is deliberately speaking falsehoods.

NYT calls out Trump on its front page for telling a lie--this time about his claim of millions of illegal votes cast https://t.co/plPG9dziA1 pic.twitter.com/CFyKU3REYO

— Steven Greenhouse (@greenhousenyt) January 24, 2017

Spicer today responded to a question about Trump’s lie that millions of illegal votes were cast during the election by saying, “The president does believe that.” This is consistent with Spicer’s message that it can’t be a lie if Trump believes it, regardless of how many times he’s been told it’s wrong or the evidence amassed against his position.

Spicer also said on Monday that reporters should assume that when he says things that are not true, he is acting in good faith and making simple mistakes -- in the same way that reporters who misreport events should be considered to have erred rather than lied.

But Trump and Spicer don’t actually adhere to that standard -- in fact, they constantly accuse their enemies (including the press) of lying.

The impetus for this entire argument was Spicer’s Saturday night claim that the press had deliberately lied about the inaugural crowd size. He did not assume they had acted in good faith and made a mistake, but instead suggested they were lying and ascribed motive, saying that photographs of the inaugural proceedings had been “intentionally framed” to “minimize the enormous support that had gathered on the National Mall.”

Likewise, on Saturday morning, Trump called the press liars. He said they were “among the most dishonest human beings on Earth,” and that they had deliberately undercounted the inaugural turnout. He added, “We caught them, and we caught them in a beauty. And I think they're going to pay a big price.” He also accused them of fabricating a rift between him and the CIA.

This is not an anomaly. In addition to frequently portraying the press at large as “lying” or “dishonest,” Trump has singled out outlets like The New York Times, Politico, The Washington Post, CNN, the Associated Press, and The Wall Street Journal, as well as journalists and pundits including the AP’s Jill Colvin and Jeff Horwitz, Buzzfeed’s McKay Coppins, ABC News’ Tom Llamas, NBC News’ Katy Tur and Chuck Todd, CBS News’ Sopan Deb (now at the Times), syndicated columnist Charles Krauthammer, NY Times’ Jonathan Martin and Charles Blow, Fox News’ Bill O’Reilly, and Politico’s Ben Schreckinger.

In addition to journalists, Trump frequently accused President Obama and 2016 opponents Hillary Clinton, Jeb Bush, and Marco Rubio of lying. He even gave Ted Cruz the nickname “Lyin’ Ted.”

The Trump administration wants impunity to spew falsehoods at an unprecedented rate, allowing the president and his team to shape the information ecosystem and push through their extremist agenda. But for that to happen, they also need journalists to give them the space to lie by refusing to call them out on their practices. At this late date, that's getting harder and harder to justify.

Sign Media Matters’ petition urging the White House press corps to “close ranks and stand up for journalism” against Trump’s attacks.