As an extension of the previous, and showing the diseased nature of a certain idea, imposing its supposed truth and thereby setting limits upon this reality. This idea would have no problem accepting the existence of the inner pathological reality of someone that is manifested by acts such as serial-killing. How could they deny this warped inner nature? However, this idea must deny for all its worth the inner reality manifested by so many of our greatest works of art, two recent ones that come to mind being the astounding Tomorrow Never Knows by the Beatles, and Voodoo Chile by Jimi Hendrix.
This strange idea being the ultimate meaninglessness of life, the absence of truth, which feels no contradiction with the insane and diseased(Freud?), while the highest manifestations of sanity are rightly felt to be utterly contradictory to the limits set upon existence and must be denied absolutely; though since this denial becomes so impossible to uphold, the denial takes the form of ignoring the worlds of highest sanity, such as embodied withing the works of purest art.
A tangential illustration of this being Lenin's declaration that he had to stop himself listening to Beethoven as it made him want to stroke people's heads with love, whereas what was required was the smashing of heads. Truth was incompatible with the idea he was surrendering to.