Hope clouds observation.
I will reference Heinlein again.In his novel, "Stranger In A Strange Land" he introduces a character called "fair witness." This website, http://dlkphotography.com/fair-witness/stranger-in-a-strange-land says, "A fair witness is a fictional profession invented for the novel. A fair witness is an individual trained to observe events and report exactly what he or she sees and hears, making no extrapolations or assumptions. A photographic memory is a prerequisite for the job, although this may be attainable with suitable training.In Heinlein’s society, a fair witness is an absolutely reputable source of information. By custom, a fair witness acting professionally, generally wearing distinctive white robes, is never addressed directly, and is never acknowledged by anyone present.A fair witness is prohibited from drawing conclusions about what they observe. For example, a character in the book is asked to describe the color of a house seen in the distance. The character responds, “It’s white on this side”; whereupon it is explained that one would not assume knowledge of the color of the other sides of the house without being able to see them. Furthermore, after observing another side of the house one should not then assume that any previously seen side was still the same color as last reported, even if only minutes before."I heard this story years ago. A tourist from New York City is driving through the deep South en route to Florida and while stopping for fuel he sees a dog acting aggressively and foaming at the mouth, he gets his tire iron from under the seat and when the dog starts to attack a small child, the tourist kills the dog. The local newspaper interviews the tourist, the reporter takes down all the information, and the headline the next day reads, "Yankee Murders Family Pet."Our hopes and our hatreds do affect our observations, but if we are aware of this, and try to put them aside, our hopes and hatreds to not blind us to the truth.
I, too, was far more a RAH fan than Frank Herbert (although he did a book regarding petroleum theft by submarines that I remember more fondly than the Dune series...)I assume you've read "The Moon Is A Harsh Mistress". That is where I first met the extremely useful idea TANSTAAFL. A concept that everyone should "grok" or suffer Murphy's wrath.