It being 25 years since L Ron croaked (or abandoned his body to continue his researches on a planet in a distant galaxy, which is what Tom Cruise and John Travolta believe, and Jerry Seinfeld, Van Morrison and Sharon Stone used to believe, or at least are believed to believe or have believed) it seemed only fair to read Dianetics and a bit of L Ron’s other stuff – Battlefield Earth: A Saga of the Year 3000 and the Ole Doc Methuselah stories from Astounding magazine – to see how he might have done it.  
And the answer is: it’s a complete bloody mystery, and not just because Dianetics is obviously nonsense. Everything is obviously nonsense. What are you telling me? When the gentleman loves the lady very very much, he climbs on top and is excused into her? And she lets him? And then there’s a baby? Excuse me? It’s ridiculous. All of it. God, Allah, Elohim, Mithras, Zeus, atoms, quarks, the Higgs boson, genes, gravity, germs: all b*llocks. All, to put it another way, stories. We may think that supersymmetry or, even more scarily, M-theory are somehow truer or more real but that’s because most of us can’t see that mathematics is another language for telling stories in – indeed, stories in which the most important thing, just as in Athenian tragedy, is not that they are necessarily true but that they are internally coherent.  
So what’s egregious about Dianetics? Never mind that it’s b*llocks. We’ve dealt with that. Why is it more b*llocks than Christianity? Why is it such a mad idea that we are actually the – I’ve probably got this wrong but it’s late and because of reading Dianetics I think I may have gone mad – invisible spirits of Thetans from a different galaxy, struggling with an accretion of spiritual vegetative matter which needs to be removed with constant application of money and a thing called an e-meter which doesn’t actually do anything except cost over $4,000, which is a pretty good return on a sort of Wheatstone bridge made from around £20-worth of components you could get from Maplin? And when that’s all done, you’re in the clear and can go on to some kind of new life.  
> further down an interesting comment by a mr. helix barkaway