I call bullsh*t.
A 5 or 6 year old does not have the vocabulary to be able to read Solzhenistyn or Joyce, and definitely does not have the reading comprehension to be able to understand the thematic principles behind them.
Before 10 years old even taking them through C.S. Lewis, J.K. Rowling, Roald Dahl, or Lemony Snicket takes an incredible amount of guidance, help, and explanation.
I'm not even sure what his first books where, but then my son was reading _Captain Underpants and the Plot of Professor Poopy Pants_, or _Ricky Ricotta and his Mighty Robot vs the Jurassic Jackrabbits from Jupiter_, _ A Portrait of the Artist as a Young Man_ was not a viable alternative.
I was 10 years old when I read Waiting for Godot, Portrait, and One Day in the Life...
No kidding but I understood the gist of it. I became more ambitious and read Platuarch [sic] during middle school... I pretty much followed the Britannica's Gateway to the Great Books of the Western World.
Remember, John Stuart Mill read works of Greek philosophy as a kid. If you don't believe that our standards have fallen so low, well look at the kiddie section of B and N.
Anyways it's back to reading Foucault for fun. Nice ride.