One of the earliest idioms we teach youngsters is to not judge a book by its cover. And that's good, because you got to teach 'em early that looks aren't everything, and it truly is what's on the inside that counts. Once your kids hit puberty, they'll soon forget this, but oh well. At least you tried.

But perhaps we just need some reinforcements to help us teach this lesson. What if instead of us judging a book by its cover, a book cover judged us?

That's exactly what Dutch artist Thijs Biersteker has dreamed up. Along with design studio Moore, Biersteker created The Cover That Judges You, an actual book whose cover knows when you're judging it.

To use it, you have to align your face with the facial illustration on the book, which then scans your face with a camera. Nxt software reads your expression to determine your emotional state. Being too expressive, either grinning or frowning, won't get you far as the screen will turn red and won't let you open the book. You have to keep your facial expression completely neutral in order for the screen to turn green and unlock the book so you can peruse the best advertising work of the year from The Art Directors Club of the Netherlands meeting.

Here's a video of the book in action.

"I often worry about my scepticism and judgement getting in my way of amazement. Judgement should never hinder relentless enthusiasm of seeing things for the first time," Biersteker wrote on the project's website.

Biersteker also told WIRED that being bombarded with so much stimulation online every day, it's hard not to greet it all with some skepticism. Indeed, with so much negativity, hoaxes and unpleasantness that we find online all the time, it's difficult to let your guard down and welcome the possibility of genuine delight to waft over you.

Then again, the fact that we're not supposed to be judgy before we open up this book full of pages and pages of what is essentially advertising has got to be cause for some alarm. But that might just be me being judgmental.