Walter Block has written a new intro to Henry Hazlitt’s Economics in One Lesson:

Writing this introduction is a labor of love for me. You know how women sometimes say to each other “This dress is you!“? Well, this book is me!
This was the first book on economics that just jumped out and grabbed
me. I had read a few before, but they were boring. Very boring. Did I
mention boring? In sharp contrast, Economics in One Lesson grabbed me by the neck and never ever let me go.

[…]

There is nothing that pleases a teacher more than when that expression
of understanding lights up a student’s face. The cartoons depict this
phenomenon in the form of a light bulb appearing right above the
depiction of the character. Well, let me tell you: I have gotten more
“ahas” out of introductory students who have read this book than from
any other. I warrant that there have been more conversions to the
free-market philosophy from this one economics book than, perhaps, from
all others put together. It is just that stupendous.

In writing this intro, Block has confirmed Brad DeLong’s worst fears:

Hazlitt doesn’t recognize any of these ifs. And that is what makes his book very dangerous indeed to a beginner in economics, because the ifs
are, all of them, important qualifications and caveats. I gather that
Tyler read it relatively early, and I am amazed that he has escaped
with so little permanent neurological and ideological damage.

If I know Walter, he’ll be delighted to confirm Brad’s fears – and frankly, I largely take Walter’s side on this.  Brad’s worried that people will ignore the ifs; I’m worried that people won’t understand that the ifs themselves require “important qualifications and caveats.”  As I write in my book:

Even
among economists, market-oriented policy prescriptions are often seen as too
dogmatic, too unwilling to take the flaws of the free market into account.  Many prefer a more “sophisticated”
position: Since we have already belabored the advantages of markets, let us not
forget to emphasize the benefits of government intervention.  I claim that the qualification needs qualification:
Before we emphasize the benefits of government intervention, let us distinguish
intervention designed by a well-intentioned economist from intervention that
appeals to non-economists, and reflect that the latter predominate.  You do not have to be dogmatic to take a
staunchly pro-market position.  You just
have to notice that the “sophisticated” emphasis on the benefits of
intervention mistakes theoretical possibility for empirical likelihood.

Under the circumstances, it’s usually best to teach Hazlitt “straight” to intro students – not, contra Levy, as a “noble lie,” but as a solid first approximation to economic truth.