What are the themes of Dead Souls?
Like much of Gogol's works, the themes are centered around the problems that are so prevalent in the Russia of his time. He uses the characters to demonstrate the corruption and theivery that was so common at the time. His characters are set up as examples of the usual people that were so willing to take part in corruption and the story shows some of the incredible situations that would result, and though it is somewhat satirical, there are moments of clear honesty and even poignant ones where Gogol makes it clear how much he cares about his country of Russia and how sad it is that these awful people are bringing it straight to ruin.
If you wanted them in a short sentence, you could simply say that the themes are obsessive paranoia, rampant greed, and even more rampant corruption.