This season wasn't as strong as the other ones, but I did enjoy the takes on the nature of truth. Varga's speech at the end summed up the series. He believed that people would believe whatever you wanted them to believe. He got Emmit out of jail by basically inventing a serial killer who was obsessed with murdering people named Stussy, a story that Gloria's boss believed because the explanation was easy and clean, even if evidence showed it wasn't true. There were a lot of little details, like when Emmit was meeting Sy and the widow at the restaurant, and he was concerned about showing up late after the death of Ray. Varga told him to just go to the bathroom immediately when he gets to the restaurant, then when he comes out of the bathroom, they'll assume he had been there a while. When the IRS guy showed up at Emmit's company to look at their books, Meemo pretends to be an attorney by simply arranging all his papers and pens in a similar way to the IRS guy and scares him off. Ray pretended to be Emmit in the sex tape, and Emmit's wife believed it.
The other thing they hammered us with is mistaken identity, which is tied to the nature of truth. From the opening scene, the East German official accuses a man of being someone he's not, and calls him a murderer. Ennis Stussy is killed only because his name and city of residence are so close to Emmit Stussy. Ennis wasn't even Ennis -- he apparently took that name from a toilet brand in an effort to become someone other than a sci-fi novelist who got duped by some con man in Hollywood. Nikki dropped an A/C unit on Maurice's head and got away with it because the apartment she was renting was under a fake name. The deputy kept calling Gloria "chief" even though she wasn't the police chief anymore (and she seemed to work out of a police station that was really a library). Ray pretended to be Emmit in the sex tape. A man confesses to killing all the Stussy victims, even though he had nothing to do with it. In the end, Varga is arrested while going under a different name, suggesting that perhaps Varga isn't his real name, either. The ambiguous ending means it's up to the viewer to decide who he sides with: Varga's world view or Gloria's?