Better to keep quiet and be thought a fool than to speak and remove all doubt.
As it happens, this is a rather apocryphal quote, having been ascribed variously to Abraham Lincoln, Mark Twain, God Almighty, and several others. A website called Quote Investigator has taken a deep dive into that quote's exact origin, but it is almost beside the point. I have read innumerable versions of this idea expressed from Greek philosophers, pop philosophers, humorists, religious texts, and so on. Like judging a book by its cover, staying silent when one doesn't have anything good to say is baked into the human experience.

I once knew a woman who felt so bad all the time that her only means of coping was to make other people feel as miserable as she was. She'd lash out, insult people, mock them, attempt to make them feel small, goad them into arguing with her, and then lay a guilt-trip on them when they lost their temper. Pleasant, right? But then again, we all know this woman, don't we? Or man.

I had a coworker at some point in the ancient past who did a good job of hiding her shortcomings by simply keeping quiet. No one thought she was a fool - quite the opposite, actually. Rather than spouting her ideas willy-nilly, she simply waited until she had a really good idea, and then spoke simply and softly. It worked; she had an excellent reputation. Still another former professional acquaintance of mine mastered a knowing-yet-slightly-inquisitive facial expression. He, too, kept quiet most of the time. Still, he had a way of conveying that he understood well, and would use the information wisely.

Sometimes the best of friends are those who spare most criticism and keep it to themselves. They only share positive thoughts with their friends, and that has the wonderful result of fostering a long history of happy memories with the people they care about. If you're interested in such things, there is a lot of research out there about the ideal positive-experience-to-negative-experience ratio. For our purposes here, it suffices simply to note that more positive feedback is better.

So the first moral of today's story is: It's best to only say things that matter, and to keep what you say mostly-useful and mostly-positive.

At EconLog, Scott Sumner writes:
Early in 2013 both Mike Konczal and Paul Krugman indicated that 2013 would be the year when market monetarism finally got tested...
Mark Sadowski sent me to a recent post by Mike Konczal. I was looking forward to reading his admission that Keynesianism had failed and that market monetarism was now triumphant. Thus I was disappointed by... [something that]... sure doesn't sound like an admission of defeat. Inflation is of course irrelevant to this issue, but NGDP is the right metric---give Konczal credit on that point. Unfortunately he has the data wrong.
Later, Robert Murphy would echo my own thoughts upon reading Sumner's post:
But being the paragon of mercy and understanding that I am, I wanted to understand how it was possible that Konczal and Sumner could look at the same data, yet each walk away with an opposite verdict.
Murphy concludes (emphasis mine):
Don’t get me wrong, I have no problem with Scott dismissing the above chart as irrelevant, or even somehow (heroically) arguing that it just proves how right he is. That’s because in macroeconomics, there are 57 moving parts, and all of us (Austrians, Keynesians, and Market Monetarists) can always tell a story after the fact. 
Rather, my purpose in this post is to get Scott and his followers to see that if you just entertain the premise for one moment that our economic woes aren’t because of “tight money,” there are lots of data to comfort you. 
When it comes to macroeconomic theory and the data, believing is seeing.
Taking a charitable view of Scott Sumner, I would be inclined to say that perhaps his ideas are so elaborate and steeped in theory that when he ventures outside the context of formal academic publications, he cannot easily explain them. Or at least, perhaps he cannot easily do so without a rigorous model.

I am willing to consider this point, but there is evidence that weakens it, in my opinion. That weakening evidence the fact that other bloggers - most notably John Cochrane, Stephen Williamson, and John Taylor - so often bring formal models into their blog posts that I am inclined to believe that they are more reflective of the kind of economists who require formality for effective communicability. Sumner, by contrast, does link to the occasional FRED graph, but mostly just cites macroeconomic data and then incorporates it into his narrative.

That is, his narrative is consistent, his rigor (when he blogs) is low, and all those who started with questions about Market Monetarism are still likely to have those questions unanswered.

The less charitable view of Market Monetarism is that there simply isn't any data set or real-world scenario that would convince them to second-guess their views. That is not a good place for an academic to be. We should have a good idea of what evidence against our beliefs would have to look like. If all data points prove the same theory, then our theory is either wrong (because we are always reconciling our belief in spite of the data), or provides no useful explanation for how the world works.

In either of these situations - that is, whether one's writing style is better-suited to another medium, or whether one's theory is simply wrong - one would find oneself writing and writing, and never really getting anywhere. There would be a lot of words without much progress to speak of.

So the second moral of this story is that, if you have a lot to explain, you should refrain from explaining unless and until you can give an effective explanation.

In all likelihood, this is unfair criticism of Scott Sumner. After all, he is a much more widely read and appreciated blogger than I am. Still, I cannot help but wonder why so many people are unconvinced by his ideas, and I am not so sure the explanation is mere ignorance of economic basics. A better economic education would not help me reconcile the fact that different economists use the same data to reach different conclusions. Thus, Sumner is in a position where he is explaining his theory more than he explains the data.

Perhaps it would have been better to have a clear explanation for his theory, so that discussions of data remained discussions of data, not theory. On the other hand, perhaps I am asking too much of the social sciences.