Thomas M. Disch: The Dreams Out Stuff Is Made Of. How Science-Fiction conquered the World. 1998.

Some qoutes about L. Ron Hubbard and Scientology.

Chapter 7
pp. 137-162

WHEN YOU WISH UPON A STAR - SF AS A RELIGION

p. 138
Leigh had worked at various small newspapers and come to the SF field, and to Walt, late in life by way of Dianetics, the embryonic form of Scientology. They left Scientology, or were excommunicated, just as the cash began to roll in and hierarchies gelled. Though driven from the fold, they continued "auditing" potential recruits. Invented in 1950 by the SF writer L. Ron Hubbard, auditing is a low-brow, do-it-yourself form of psychoanalysis, in which the auditor-analyst roots up "engrams" - repressed traumas often encoded in psychosomatic ills. With a copy of Hubbard's Dianetics in hand, a little black box called an e-meter, and the right manner, anyone could play doctor.

p. 146
Most New Age prophets and profiteers derive whatever systematic theology they have to the scheme set forth in Science and Health: Only the spiritual world is real; the physical world, including our mortal bodies, is an illusion. Those who can see through that illusion will enjoy good health, immortal life, and Porsches. The most enduringly successful of Christian Science-descended religious in our time has been Scientology, the brainchild of the hack writer L. Ron Hubbard. As an SF writer, Hubbard had a neglible impact on the field, and it is doubtful that without the controversies surrounding Scientology and its immense success, his fiction would be read or remembered today. The Science Fiction Encyclopedia's estimate of the merits of Hubbard's early SF, which mostly appeared pseudonymously in the more downscale pulp magazines of the 1940s, is not the stuff a writer's dreams are made of:

His best-known early novel, Final Blackout (1940), grimly describes a world devastated by many wars in which a young army officer becomes dictator of the UK, which he organizes to fend off a decadent USA. It cannot be denied that he book veers extremely close to the fascism its text explicitly disavows. But SF was clearly not Hubbard's forte, and most of his work in the genre reads as tendentious or labored or both….In general his early work, though composed with delirious speed, often came to haunt his readership, and its canny utilization of Superman protagonists came to tantalize them with visions of transcendental power. The vulnerability of the SF community - from Campbell [editor of Astounding Science Fiction] and A.E. Van Vogt down to the naivest teenage fans - to his lure of transcendence may help account for the otherwise puzzling success first of Dianetics, then of Scientology itself.