Most readers probably recognize the aviation event called spatial disorientation. It occurs when the pilot's senses don't agree with the physical reality of the plane's motion and its relation to the ground. The pilot can't tell up from down or whether the plane is flying level or in a turn. A number of airline fatalities are directly related to spatial disorientation. Certain things exacerbate the problem, for example alcohol and some drugs including anti-depressants, anti-histamines, and some pain relievers (not to mention illegal drugs).
Why do I bring this up? Because I think this elucidates the term diabolical disorientation. Many people today are living in an upside down world that they insist is right side up. They are often flying blind like the pilate who enters a cloud losing all contact with visual cues. That's when instrument flying becomes crucial. And if you don't have and use the instruments, you're headed for a crash.
