User blog comment:TheAnime/What are titans?/@comment-25107612-20140803064101

The more advanced theories regarding Titans regularly involve a darker, greater plot, usually by the human government, where the Titans are indeed a means of authoritarian control and technological advancement was banned on purpose to protect the status quo.

It is suggested that human civilization is much older than it looks like, a key time frame seems to be 2000 years. It is possible that civilization was more advanced in the past and created the Titans on purpose as part of the wars which happened frequently back then (this is mentioned in both the manga and anime.) The current "way of life" could be a plot in order to avoid mankind fighting itself again, perhaps because the last war was so destructive that it nearly killed all humans. The keys are the Reiss family (which is 2000 years old and seems to be very important) and the Beast Titan who can turn humans into Titans and whose nature is unclear. The humans from outside the walls - who are hostile to the human government - could be rebels who attempt to end the plot.

Regarding the Titan bodies: The question is whether it's a pure fantasy or a science fiction scenario. Titan bodies could be created by nano machines, direct energy-to-matter conversion (note the energy burst every time they shift, and the heat and little weight of the Titan body), by the human soul, or they don't even exist in reality, and the "whole world" (the rather small part where the story happens) has been warped by some mind-deforming energy field, and nothing is what it seems like. That's possible because Eren can control Titans by telepathy, and the woman who looks very similar to him (possible a relative) is able to delete memories. People like Reiner and Berthold are from outside of the illusion.

Another issue are the walls, which are bowls in truth and seem to be build into something what looks like a very huge crater, either created by a meteor or by war. The basement in Eren's home could lead below the bowls to the crater itself. If that was true the origin of the Titans could be tied to a meteor impact, but that is speculation.