Twin Peaks is a story that can be addressed from multiple points of view. Staying with a reductionist view, qualify it as “the story of a murder” o “the history of a people” It is not to understand what Mark Frost and David Lynch mostly wanted to tell us.
On this basis, We can say that Twin Peaks is…
This is a key point to understand the series. “Twin Peaks” translates as “twin hills”, and not by chance. The existence of the white lodge and the Black Lodge is the base from which parts all the duality in the world. There are certain elements that are part of a lodge in Twin Peaks, and others who are on the opposite side. Windom Earle is the reverse of Cooper, The dwarf is the reverse of the giant, the village of Teresa Banks is the reverse of Twin Peaks… In the symbols section, you can read a more in-depth analysis on the subject.
Once understood this point, is divided in turn into two other, opposite and complementary at the same time: dual.
The pure souls of Twin Peaks are constantly being corrupted by the influence of the Black Lodge. First attempts to subjugate Laura by Leland/BOB, but fails. When appears in scene Dale Cooper, someone naturally connected with the white lodge, the focus of the Black Lodge is on it. Finally they get corrupt you.
As a natural opposition to the corruption that permeates the people (the famous universal balance, the duality), in Twin Peaks there's love overflowing. Surprised by the amount of trouble of couple and horns that we see throughout the series. James Hurley, For example, He falls for four women throughout the series. Audrey Horne falls for Cooper, and a couple of weeks after falls for a newcomer. This healthy love that pervades Twin Peaks counteracts to BOB and the rest of the Black Lodge.