"9. Fancy rests upon images which have no real existence. This means that these images have no real existence in so far as they are conjured up by men themselves, constructed within their own mental auras, energized by their will or desire and are consequently dissipated when attention is directed elsewhere. "Energy follows thought" is a basic tenet of the Raja Yoga system and is true even where these images of fancy are concerned. These fancied images fall primarily into three groups, which the student would do well to consider. 1. Those thought forms which he constructs himself... 2. Those thought forms which are created by the race, the nation, the group or the organization. Group thought forms of any kind... form the sum total of the "great illusion." Herein lies a hint to the earnest aspirant... 3. That thought form created by a man since his first appearance in physical form, and called the "Dweller on the Threshold." Being created by the lower personal self and not by the soul, it is impermanent and is simply held together by the man's lower energy. When the man begins to function as the soul this "image" he has created, through his "fancy" or his reaction to delusion, is dissipated by a supreme exertion. It has no real existence once there is nothing in the aspirant to feed it, and the realization of this enables him to free himself from its thraldom."
January 1, 1970
https://en.wikiquote.org/wiki/Yoga_Sutras_of_Patanjali