It does not to have be restated that Blade Runner is an orchestral masterpiece of the Post Modern condition. But I just did.
Although the exact nature of what 'Post Modernism' is is amorphous, ambiguous and changing, many of the ingredients seem to show up: disruption of the social order by the Replicants, conflicting and equal perspectives of the Replicants v. Humans, mixing of the inorganic and organic vis a vi the Replicants, and the genre hybridity of Film Noir and Science Fiction.
Regarding the last, and for the sake of this response, I'm going to leave that out. Why? Because this movie is blatantly Film Noir. If anything, this is the most base and obvious of interpretations. The film utilizes the femme fatale, the cynicism, the dark palette, the long shadows, the brooding protagonist unable to control his desire for the woman etc etc etc.
Any asshole who takes a first look at this movie can purport that this is a genre fusion. But that's not where the cleverness lies. This movie is steeped in layers and symbology for the viewer to discover and rediscover over multiple viewings. And if Ridley Scott intended anything of his audience, it's to look deeper. Because he doesn't even bother to nuance his use of these two genres.
And now for the fun. The three themes I would like to discuss in this are the influences on the film, the use of challenging perspective & the idea of personal truth, and the motif of sight.
The first and most obvious influence on Blade Runner is Metropolis. Itself a dystopian vision of the future, Metropolis is both visually similar AND uses the idea of a replicated human being. For those unfamiliar, although I suspect that either the T.A. or Rosetta reading this is keenly aware of this film and its cultural significance, the film is about:
The journey of one man to unite the lower and ruling classes of a 'utopian' future world where the lower class lives underground, unseen and unknown by those above. During this time, the woman he desires, Maria, is copied into the body of a lookalike robot.
Blade Runner, aesthetically and thematically is obviously uncanny. The truly interesting thing here is that the Maria robot is fundamentally evil. Without a doubt, the robot is used to cruel ends, a very one dimensional character. In a plot analysis sort-of-way, she is just furniture to be used as a prop to get from point A to B to C. Additionally, all the citizens of Metropolis don't know about the cruel abuse happening beneath their feet.
Blade Runner sharply contrasts both those features. The humans are aware that they use Replicants as off world slaves. Additionally, the Replicants aren't pure evil. They just want to live, love and be free from fear. More on that in the perspective portion of this response.
Here's where things get borderline conspiracy theory.
The Bradbury building in Los Angeles is used as the site of JF Sebastien's home, and the final battle between Deckard and Roy. That building was built in the 1890's by George Wyman who based the architecture on a novel by Edward Bellamy. The novel is about a Utopian future where all the problems of the 1880's are solved by socialism. What was this book called? "Looking Backward." I can't make this shit up.
So here we have Blade Runner, a dystopian Noir vision of the future which is based heavily off the film 'Metropolis' which itself is a vision of a dystopian future disguised as a utopian future. The building where the final confrontation of Blade Runner is filmed is based on a book about a vision of the future called "Looking Backward."
It seems as if Scott has just taken a sample platter of all the previous 'this is what the future will be like' works and mixed them together.
But Scott's interpretation is so much more titillating because of his post modern use of personal truth and perspective. Which brings us to theme number two.
(For the sake of clarity, I'm going to talk about the use of sight and perspective together although they are separate themes.)
My favorite aspect of this film is the idea that the Replicants are just as important as the humans. Scott presents the Replicants with a fully fleshed perspective of their own. They don't want to live in fear. They don't want to be slaves. You may be cheering for Deckard to slay these violent antagonists, but by the end, I'm sure you're also cheering for him and Rachael to be together.
Scott also uses the theme of sight throughout the film to weave the idea of perspective into the script. One of the earliest examples of this in the film is when Roy and Leon visit the eye maker. Roy tells the eye maker, "if only you could see the things that i've seen with your eyes." This is said all the while that Leon is putting these synthetic eyes all over the scared man.
The motif is built on later when Deckard pursues Zhora and tells her a lot of guys would make holes in the walls to get a look at a beautiful woman.
And the final and easily most piercing of these examples is Roy just before he dies tells Deckard, "I've seen things you people wouldn't believe."
Scott is careful to make subtle suggestions to look at life through the perspective of the replicants as early as possible, and is diligent in reweaving that concept throughout the movie so you don't forget.
That last line that Roy says to Deck is also shortly following his rescue of Deckard himself. It was easy to dismiss the Replicants the entire film up until then. It seems that Roy was the closest thing to a singularly evil enemy but his saving Deckard really drove the point home that Replicants were no more or less evil than humans. Nor more or less valuable.
In short, I believe this film's most valuable contributions to Post Modernism are the challenging of perspective. Your enemy's reality is just as potent as your own.
Edward Bellamy's 'Looking Backward' only provided a fantastical look at the future that solved all the present day problems. It was escapism. Metropolis depicted a future world that appeared utopian on the surface but was fundamentally dystopian. However, this was done with archetypal and benign characters.
Blade Runner has provided the next evolution in style and thought; all perspectives are true.