Around the dinner table, the conversation was lively. Thank you but for now, the forum has been archived.
Something that I've been thinking about recently that has me confused, not that everything is crystal clear in this story, but is Dale's doppleganger Mr. C an entity unto himself or does he only exist as a vehicle for Bob? Hawk, or someone, described the doppleganger as your shadow self. Can the doppleganger exist in the real world without Bob? Was the person that killed Laura Leland's doppleganger? And if Bob left Leland as he died was that Leland's doppleganger or was that Leland himself that died on the cell floor?
No it was Leland with Bob in control. When Leland was a boy Bob asked to be inside him, and Leland said yes. Watch that scene again.
Agreed. The degree to which Cooper's doppelganger can exist without BOB's involvement has yet to be seen, depending on what happened in Part 8 this week. But Leland was definitely himself, possessed by BOB.
I'm also struggling with the use of doppelgangers in TP/TPR. My reading is that we have the following possible doppelgangers:
1) Coop / Mr C: I think this one is pretty well established (S2/FWWM/S3), but as noted, what if any relation is BOB to the existence of a doppelganger? Also, can the original Dougie (S3) be considered a doppelganger or is he just a manufactured tool of Mr C?
2) Mike's arm/tree / arm's doppelganger: before Coop leaves the Black Lodge/Waiting Room (S3) the arm announces it has a doppelganger, doesn't it? What was the significance of that?
3) Laura / Laura's doppelganger: I think this has been intimated during the series. It seems that sometimes Coop is talking with Laura in the Black Lodge/Waiting Room ("Who are you?" "Laura Palmer") and at other times with her doppelganger (doesn't she say she's not Laura, but knows someone like her?)
All suppositions on my part, any light shedding (or theories) welcome.
In response to the Arm's doppelganger. I believe that it was the the static-tree Cooper sees before he falls into the ground while in the Red Room. Mike says later "You... were... tricked... now one of you must die". Guess he was tricked by the Arms' doppelganger.
We saw the arms doppelganger in the final episode of the original series, they can be identified by the white eyes
I believe that the doppelganger Cooper is an autonomous entity that happens to carry Bob around for the ride.
We see BOB show himself in the mirror at the prison and Mr C comments "good your still there" (paraphrased). Then we see BOB outside his body after he's shot....I believe the woodsmen are pushing BOB back into Mr Cs body. So I think its a symbiosis. In TP when Coop is in the Black Lodge he's asked if he would trade his soul for Annies and after he agrees its mentioned that his soul couldn't be taken which is probably why Coop and his doppelganger race to leave and whomever got out first won....I'm surmising that BOB has to have a body to manifest in and a doppelganger is a perfect foil but unlike possessing a human he can only stay out of the lodge for 25 years.
If BOB had indeed left MrC in Part 8, then we are seeing MrC as an entity unto himself. Same evil character, but BOBless.
It would seem, they are all unique, and the other factor would be the "different species" mentioned in the Secret History
We can also note that Coopledanger, does not have the drastic shifts Leyland did, which could be attributed to level and duration of control Bob had. Was he sometimes just an influence, being able to take total control for periods of time, or was he in total control at all times?
In short, Bob ('an inhabiting spirt'in a Dopleganger would be a symbiant, but in a human more of a parasite/infection
Hawk says that his people call doppelgänger "dweller on the threshold". I haven't found this term in first peoples' mythology, however it's quite important term in hermetic/occult/freemason-spiritual tradition. According to that, the "dweller" is part of us as a concentration of all negative (all previous karma). On the path to the light everybody has to face this dweller (or - as sometimes it is called) - guardian of the threshold, which is actually part of you. By combating it, we (together with the "dweller") can access the ultimate light. This concept is similar to the Jungian concept of shadow. From this point of view, The Return is a story about Cooper's ultimate trial by combating the shadow self. Now, interesting turn is, that dweller (being already dark enough) is "enhanced" by a demon, which is "riding" him as a vehicle, apparently. Dweller has his own personality apparently, and is in control/symbiosis with BOB parasite. Somebody (Philip Jeffries - or his dweller?? - or ???) wants BOB out of doppelgänger to be "with BOB again". A bit messy and complicated, however it is very interesting how it will turn out in the end.
Some initial info about dweller for those, who are interested (google has many nice results too):
https://en.wikipedia.org/wiki/Dweller_on_the_threshold
https://theomagica.com/the-dweller-on-the-threshold/
Fire walk with 
