We are products of the Paleolithic age, a period of many thousands of years in which the Homo species developed the unique adaptations that make them human. In the Paleolithic period we lived in small tribes. The information we had was limited. But it was reliable. When a fellow tribesman came running into camp with word that another tribe was about to attack, we had a pretty good idea of how real and how important that information was. We grabbed our spears.

Now, we have a lot more of a different kind of information for which our Paleolithic brains are not well adapted. It is high in quantity, low in quality. Nietzsche referred to it as ‘wissen.’ As opposed to ‘erfahrung,’ – direct, personal, particular knowledge – wissen refers to ‘what everyone knows’; like we might know that America has a problem with violence or we might know that Berlusconi is a rascal or that Abraham Lincoln loved the slaves. It’s the stuff you read in the newspapers and hear on TV.

Until the invention of TV, radio and the Internet, the volume of this ‘public information,’ as I like to call it was only a fraction of what we get today. Just recently, a New York Times article estimated that the typical American receives as many as 5,000 advertising messages every day.

Advertising, news, opinions, data of all sorts—it is remarkable how much more we “know” today than we used to. In 2013, we knew, for example, that the unemployment rate was above 7%. We knew Iran posed a threat to our safety. We knew education was the way to get ahead. We knew the Republicans were trying to block tax increases and that global warming could tip the world into a climatic disaster. Joe Jones, running for the office of Sheriff, was a ‘friend of the people.’ LavaX – a cleaning product – would leave your tub “as clean as an operating table.” But what did all these things mean? Were these things even true? Did anyone know? Was there any way of knowing for sure?

Like infectious social diseases, public information is made possible by modern, large-scale life. Millions of people can now have a conversation about something none of them really knows anything about. It can be fun. But it can lead to serious itching, or as I call it, ‘public thinking.’

At an investment conference in 2002, a guy came up to me making conversation. 9/11 was fresh in our minds. And the Bush Administration was pushing for an invasion of Iraq.

“I guess we’ll have to go in and clean that place up,” he said.

A million nuances, an infinite number of real ‘facts’ based on experience and direct observation, a whole universe of assumptions, misapprehensions, muddled thinking, all reduced to a single phrase. And that, there, is ‘public thinking.’

Had he ever been to Iraq? Had he ever met an Iraqi? Did he speak the language? Where was the detailed, specific, precise real knowledge that you would need to make sense of it all? What, exactly, was unclean about Iraq? And how would this lack of hygiene be scrubbed up by a foreign invasion?

Constructing a public policy out of public thinking is like building a skyscraper out of marshmallows. The higher you go, the squishier it gets. Because the information blocks themselves are not solid. Instead, they are combinations of theory, interpretation, guesswork, spin, hunch and prejudice.

It takes a certain kind of brain to appreciate the emptiness of public information. Most of us are too earnest, which is to say most people are better adapted to the time in which they evolved. Most of us have stone-age brains. We regard all information as though it is rock hard. When Colin Powell told the world that the Iraqis had ‘weapons of mass destruction,’ most people — trapped in the noise of modern life — believed him. They took it as information of the same quality as the alarm sounded by the fellow who ran into camp warning of an imminent attack.

‘Public information’ contributes in an important way to hormegeddon. Like sugar, human consumption of news and information has soared since the 18th century. Both sugar and public information are tasty in small quantities. But eating large quantities of sugar rots your teeth and may give you diabetes. It is also self-perpetuating, as eating sugary food takes away your appetite for real food. So too with public information, your ability to make good decisions rots as your appetite for useful information decreases.

Public information is the stuff on which our governments, our social programs, our wars, and our money (including fiscal and monetary policies) now depend. It is the body of facts with which our consent is informed. It is the faux-granite upon which our public policies – involving trillions of dollars and interfering with countless private plans – are erected. And like everything else, public information obeys the rule of declining marginal utility. A little may be a good thing. But ‘too much’ leads to trouble. It gives you the impression that you know something that is really unknowable. Phony knowledge then leads to foolish action. Soon, you are on the road to hormegeddon.