From The 1955 Book by Milton Mayer "they thought they were free", p. 176
Another colleague of mine brought me even close to the heart of the matter – and closer to home. A chemical engineer by profession, he was a man of whom, before I knew him, I had been told, “He is one of those rare birds among Germans—a European.” One day, when we had become very friendly, I said to him, “Tell me now—how was the world lost”
“That,” he said, “is easy to tell, much easier than you may suppose. The world was lost one day in 1935, here in Germany. It was I who lost it, and I will tell you how.”
open up Milton's book at Amazon, "look inside" with search term "chemical engineer" to learn how.