Goethe's line about self-deception is one of the more famous; it can be found on t-shirts, coffee mugs, and many personal blogs throughout the WWW. Although it is so popular, many may not take much time to consider what Goethe actually wrote in his piece, where the line is typically taken singularly and out of context of his original writing.
If we take the quote to mean that one is never a victim of deception but instead one allows themselves to be deceived or is ignorant about their own beliefs or other knowledge so they are deceived, we have a starting point.
One example is how the town of Maycomb is first perceived but the reader in the opening of the novel. As it is described by Scout as the narrator (older Scout looking back, remember) most picture a sleepy southern town where everyone knows everyone and has a simple and defined role. It seems to be a happy place to have a childhood full of sunshine and amiable and colorful characters. However, the reader is quickly reminded about how society in the deep south of the 1930s functions as the hidden murk beneath the nice exterior of Maycomb is slowly exposed. One of the early moments in the story where a light is shown on the dark side of the town is when Mr. Radley uses the N word to cast blame without any evidence that a black man had been snooping around his property. The town quietly accepts this racist charge.
A second example is the disappointment Jem feels after learning the outcome of the trial. Jem is a young man well versed enough in the structure of his town to realize that a black man was never going to have a chance to be found not guilty of a crime against a white woman. However, he allows himself to believe that the rest of the town views things with the openness and integrity of his father, Atticus, when Jem has been confronted with example of example of the bigotry of people in his town, even within his own family.