Espionage, for the most part, involves finding a person who knows something or has something that you can induce them secretly to give to you. That almost always involves a betrayal of trust.
“The brain's calculations do not require our conscious effort, only our attention and our openness to let the information through. Although the brain absorbs universes of information, little is admitted into normal consciousness.”
“A slight daily unconscious luxury is hardly ever wanting to the dwellers in civilization; like the gentle air of a genial climate, it is a perpetual minute enjoyment.”