Between the idea
And the reality
Between the motion
And the act
Falls the Shadow
— T. S. Eliot, "The Hollow Men"
A passage quoted here on this date in 2005—
Douglas Hofstadter on his magnum opus:
“… I realized that to me,
Gödel and Escher and Bach
were only shadows
cast in different directions
by some central solid essence."
This refers to Hofstadter's cover image:
Also from this date in 2005:
Midrash: Hearts of Darkness.