In a very thoughtful article, Christopher Mims tackles this issue in MIT’s Technology Review.  Here’s an excerpt.  I suggest you read the whole thing:

Unlike books, which are one of the few media that do not require a secondary external device for playback, e-books put additional barriers between readers and knowledge. Some of those barriers, as I’ve mentioned, consist of Digital Rights Management and other attempts to use intellectual property laws as a kind of rent-seeking, but others are more subtle.

One in five children in the U.S. lives below the poverty line, and those numbers are likely to increase as the world economy continues to work through a painful de-leveraging of accrued debt. In the past, the only thing a child needed to read a book was basic literacy, something that our public education system in theory still provides.

Imagine Abraham Lincoln, born in a log cabin, raised in poverty, self-taught from a small cache of books, being stymied in his early education by the lack of an e-reader. And there are countless other examples — in his biography, Bob Dylan recounts spending his first, penniless days in New York City lost in a friend’s library of classics, reading and re-reading the greatest poets of history as he found his own voice.

Sure, these are extreme examples, but it is undeniable that books have a democratizing effect on learning.