Yes, this is Jekyll and Hyde

Rating: 10/10 (19 April 2018)

I do not hear it discussed too often, but FIGHT CLUB is essentially an adaptation/re-telling of Robert Lous Stevenson's THE STRANGE CASE OF DR. JEKYLL AND MR. HYDE. Yes, there are significant differences, but at it's core, the main points are there.
First, the two sides to the character being played by different actors isn't unique, it's what Stevenson intended. He writes Jekyll and Hyde as two different people, both physically and mentally and they approach each other as individuals too. FIGHT CLUB essentially does the same. These are two different people with two different mindsets. The main difference being that Tyler and the narrarator only appear different to each other; physically they are the same to everyone else.
Some of the key elements thematically are that both are about breaking free of the societal limitations fo the time. Durden is free of consumersim and capitalistic expectations. Hyde is free of Victorian reservations and norms.
Additionally, Hyde/Durden both start off with less of an influence but eventually fight to take over the other personality in its entirety.
At it's heart this is a great movie and a great adaptation/interpretion (call it what you will). It gets better with each viewing and reading (the book is even better).