|The subject of this article has no official name.|
It is a fan-given name as substitute for lack thereof, and should not be considered as part of the Attack on Titan universe.
|One hundred and seven years ago...Humanity that fled into these Walls...The King had altered their memories to make them easy to rule. That was my father's theory.|
|— Erwin speaks to Dot Pyxis about his father's theory|
Mr. Smith was a tall, thin old man with short blond hair, circular glasses, and an unkempt beard and mustache. He had distinct cheekbones and wrinkles on his face, and wore a white shirt with the sleeves rolled up and dark gray pants when teaching his class.
Mr. Smith appeared to be highly intelligent, considering how he theorized about the Walls. He also cared deeply for his son's future, so much that he did not reveal his "dangerous" theory in his history class for his sake and the students', but later told Erwin.
In Erwin's youth, Mr. Smith was a teacher in their hometown. One day he was teaching history when a young, bright-eyed Erwin Smith asked him a question. He vaguely avoided it, ending class soon after. When they made their way home, he sat Erwin down and gave him an honest answer to his question based on what he believed. He mentioned that the history books, distributed by the government, were full of mysteries and contradictions. He believed that it was near impossible for humanity not to have passed down an oral history. Instead, the only way to ensure that humanity forgot about the history before the Walls would be to alter their memory in some way.
Due to Erwin's naivety, the Military Police caught wind of Mr. Smith's theory. He was then secretly detained and tortured for what he knew. His body was then dumped in a far-off town, made to look like an accident.
When Nile Dawk is speaking to the other Military leaders about his past with Erwin, he reveals that the question he asked his father that led to his subsequent death and Erwin's dreams of knowledge about the outside world was "How do we know there's not more humans outside the Walls?".