The effect of disordered thinking on Rudolf Steiner

An excerpt from a lecture given by Rudolf Steiner on June 5, 1912:

I was walking yesterday along a certain street. My gaze fell, quite involuntarily, on a particular spot in a bookshop window. All at once I felt as though I had been stung — really just as though a gadfly or a bee had stung me! Spiritually, that was how I felt. I was curious to know the cause. To begin with, I could find nothing in the shop window that could have stung me like that. But when I looked carefully, I saw a book lying there on which was a legend, intended, so it appeared, to vindicate the trend of thought in the book, the author meaning to describe with this saying his own attitude of mind. But why should it sting me? You will see presently. These were the words:

“Your speculative churl
  Is like a beast which some ill spirit leads,
On barren wilderness, in ceaseless whirl,
  While all around lie fair and verdant meads.”*

and underneath was written “Goethe: Faust.”

But who says this in Faust? Mephistopheles says it! These are not the words to choose when you want to quote Goethe! They are words he puts into the mouth of Mephistopheles. And if they are quoted seemingly in honest approbation of their meaning, it argues a disorderly thinking, The author wants to cite Goethe; but inner reasons compel him to quote Mephistopheles — that is, the devil. That shows me that something is amiss with his thinking. The sting I experienced came from the displaced and disordered thinking.

Source: http://wn.rsarchive.org/Lectures/Dates/19120605p01.html