There are considerable clues that indicate that Dianetics is not a science. For example, Hubbard’s a priori idea that a science’s aim is to find a single source to all mental ills appears to be a convenient postulation, not being a confirmed fact and neglecting all knowledge accumulated by humanity up to today. He is ignoring natural laws on purpose by stating that a science is built on “definite axioms”. We know that any scientist is working out from a null-hypothesis and that he relies on data collected empirically. Therefore, Hubbard is simply wrong by claiming that a science is based on a set of convenient truisms. Science is a matter of discovery and not stipulation.
Other questionable theses, declaring that Dianetics is a science, can be noticed. Hubbard’s theory of the human mind has almost no overlap with our knowledge of the brain and modern neurophysiology. Hubbard states in his book that the mind has three parts. "The analytical mind is that portion of the mind which perceives and retains experience data to compose and resolve problems and direct the organism along the four dynamics. It thinks in differences and similarities. The reactive mind is that portion of the mind which files and retains physical pain and painful emotion and seeks to direct the organism solely on a stimulus- response basis. It thinks only in identities. The somatic mind is that mind, which, directed by the analytical or reactive mind, places solutions into effect on the physical level." According to Hubbard, the single source of insanity and psychosomatic ills is the engram. The engram postulate bases on, what Hubbard calls “scientific facts”, but in reality they cannot be proved or disproved. Hubbard makes claims that common medical disorders are due to these engrams, which are to be found in one’s “engram bank”. However, this bank has no known locus in a human body. It seems that Hubbard can claim anything he wishes as long as it is not possible to prove. This is the case here. Keeping in mind that a science must be discoverable and not claimed, we have found another piece of evidence indicating that Dianetics is a pseudoscience.
Hubbard claims that a significant amount of data was accumulated in advance of the publishing of his ‘bible’ and not a single exception to his theory has been found. Here we are forced to believe his word since his presented data are all formatted as anecdotes or designed examples to best fit the context. A further hint that Dianetics is full of inconsistent claims is provided here: “Several theories could be postulated as to why the human mind evolved as it did, but these are theories, and dianetics is not concerned with structure". It does not concern him that engrams, which permanent changes in the cell, were never observed and cannot be observed, and are undetectable as physical somatic structures of the body.
Hubbard reaffirms the reader of the ‘fact’ "a single source of all insanities, psychoses, neuroses, compulsions, repressions and social derangements." He further claims that "Invariant scientific evidence as to the basic nature and functional background of the human mind." Additionally, his type of science is required to understand the "cause and cure of all psycho-somatic ills...." And shortly after, as if to protect himself against massive numbers of ‘California-typic’ law suits he contradicts himself by saying that it would be unreasonable to expect a science of mind to be able to find a single source of all insanities, since some are caused by "malformed, deleted or pathologically injured brains or nervous systems" and some are caused by doctors. He reveals the weakness of his own claims by reaching for the defensive position. He lacks of qualified arguments in order to persuade the intellectual and educated man. Example by example Hubbard cancels out his claim by defensive counter-statement, which he is forced to make due to his pseudoscientific positive hypotheses.
Hubbard no scientist, but rather a man that attempts to trick, what one would call, less or misinformed people by disobeying all rules of conduct, of what we commonly know as science.
http://www.skepdic.com/pseudosc.html
Hubbard, Dianetics: The Modern Science of Mental Health, The American Saint Hill Organization, 1950.