Dear Cecil:
Why does the U.S. dollar bill have the image of a pyramid with an eye in the capstone? Someone told me that it has something to do with a shadow society that secretly rules the country. If they're so secret why would they be so obvious about their insignia? I want the straight dope--that is, unless they've gotten to you too. --Jason K., Scarborough, Ontario
Cecil replies:
They haven't. Ticks me off. Why should guys from the dailies get all the payola? As for the apparent paradox of a secret society advertising itself in one of the world's most conspicuous places, some say that's the beauty of it. The conspirators are geniuses, see? They know that the more they make themselves obvious, the more they'll be invisible. If that sounds like a classic line of malarkey--bud, you're starting to catch on.
As you know if you've read the fine print, what you see on the back of a dollar bill is the great seal of the U.S., established by Congress on June 20, 1782. The official interpretation is that the pyramid represents strength and durability. It's incomplete because so is the work of building the nation. The eye in the triangle is the all-seeing eye of providence.
http://www.straightdope.com/classics/a5_022.html