L. Ron Hubbard claimed that the source of all problems were 'engrams' - traces left in the "Reactive Mind" by past events, even when the subject was unconscious. By re-living these events over and over again, their effect would dissipate and the patient would be cured. One scientific test was actually approved by Hubbard, in which a subject was exposed to information while unconscious, and later questioned to try and recover the information. It failed, but this did not deter Hubbard, who simply ploughed ahead with more and more bizarre descriptions of engrams. He appears to have had an obsession with abortion, and lists dozens of engrams caused by attempted abortions. Then he spread his net wider and included engrams caused in past lives The standard ploy to sell the concept of engrams to the 'raw meat' is the 'pinch test' in which the subject is pinched, and then hooked up to an E-Meter and aked to remember the pinch. The needle moves, but subsequent attempts to remember cause smaller movements. This is alleged to show an engram being created and removed.

The falsity of the engram concept is admitted in Scientology's own works, as for trainees to reach 'Clear' they have to attest to the 'Clear Cognition' which is "I am mocking up my reactive mind" in other words, the whole thing is an illusion. If the student can afford to take the OT ("Operating Thetan") courses, they are told that the "real" problem is infestation with invisible brainwashed aliens or "BodyThetans".