“Time is speeding up. And to what end? Maybe we were told that two thousand years ago. Or maybe it wasn’t really that long ago; maybe it is a delusion that so much time has passed. Maybe it was a week ago, or even earlier today. Perhaps time is not only speeding up; perhaps, in addition, it is going to end.” — Philip K. Dick 
‘Memories, you’re talking about memories.’
Los Angeles. November, 2019. Industrial smokestacks belch fire into the sky and flying cars glide through the haze. Architectural curiosities of the city, the Bradbury Building of 1893 and the Ennis-Brown house of 1924, are overwhelmed by twenty-first century megastructures. Rising from the mass of this megalopolis, the twin pyramids of the Tyrell Corporation emulate the pyramids of ancient Egypt. Interiors are Mayan-styled and decorated with Bonsai trees, the populace wear twentieth century fashions and go shopping in Arabian bazaars. The city is being devoured by acid rain and obliterated by retrofitting, and likewise reality is collapsing as geography and history are swallowed up by the cultural schizophrenia. This is a dreamscape where everything is ending and the spectacle of disintegration is rendered in intricate detail. The world is at once realistic and unreal in Blade Runner.
The Nexus-6 Replicants are the embodiment of this terminal condition: biological high technology that is dying by design, they are without a past or a future. Replicants are simulated humans, stronger and at least as intelligent as their creators, a copy so perfect it is superior to the original – evolution, a copy without an original. Dr. Eldon Tyrell declares his creations to be
‘more human than human’, but the perfect simulacra are not without imperfections. Lacking the memories that are so necessary for the construction of self, the Nexus-6 Replicants are afflicted by an identity crisis. This crisis has been resolved in Rachael by simulating history, implanting memories to fabricate a past for her. The Tyrell Corporation has constructed her identity as it has engineered her body. Tyrell describes this procedure as gifting the past, unaware that his gift to Rachael has implications for all of humanity: she is a simulation so perfect that it has made suspect the reality it simulates. At the core of the film is this identity crisis – this reality crisis.
Blade Runner is a film about the discovery of truth and the disintegration of memory in a hyperreal  future society of failing signs and signifiers. From the opening credits, the Vangelis score speaks the language of memory: beautiful and perilous and unbearably fragile. An atmosphere of doubt and paranoia pervades the film, personified by Deckard, the detective-assassin who searches for the truth in the shifting sands of this landscape, uncertain of his actions at every move. Bryant orders him to the Tyrell Corporation to try the Voight-Kampf test on Rachael.
‘And if the machine doesn’t work?’ asks Deckard, knowing Bryant has no answer. Rachael questions Deckard’s ethics, asking if he has ever retired a human by mistake. He says no.
‘But in your position that is a risk?’ she asks him. It is not his righteousness, but his rightness that is in question. How can he know he has never retired a human?
The question of doubt is soon raised on the macro scale. Tyrell explains why Rachael is so difficult to detect and the implications of her implanted memories are obvious to Deckard.
‘How can it not know what it is?’ he asks incredulously. ‘How can I know what I am?’ is the question he means to ask. The ability to fabricate memories and construct identities has made all knowledge a source of doubt and it forces Deckard to question the authenticity of his own reality. Just as Deckard has the Voight-Kampf test to assure him that he is retiring Replicants and not humans, Rachael has a photograph to provide the physical evidence of her fabricated childhood.
“Photographs are essentially history”  Ridley Scott has argued, but the photographs he imagines in Blade Runner – like the history they represent – are not to be trusted.
Rachael goes to Deckard with the photograph she claims to be of herself as a child with her mother, but he knows her childhood memories are false and the photograph is no guarantor of authenticity. Deckard confronts Rachael with his destructive knowledge, she cries and he is suddenly ashamed of his cruelty. He offers her a drink, but she leaves when he goes to fetch a glass. When Deckard returns he looks at Rachael’s discredited and discarded proof, the photographic trace of a remembered past now revealed to be the record of a false memory. It is an image of any mother and child. As he looks at the photograph he realizes that his attack on Rachael was self-harm: his own collection of old photographs are the proof of a history before he was born, from a mythical past he never experienced. Deckard knows ultimately he can give himself no assurance that he is not also a Replicant.
While he is inspecting Rachael’s photograph, the image animates fleetingly and Deckard relives the remembered sights and sounds of that moment from the past. The moving still  is not a signifier of memory, but the memory itself encapsulated in physical form – Rachael put her faith in this image and remembered the past through it. Leon’s photos are so important to him that he tries to recover them before Deckard can find them. Perhaps it is appropriate that they appear to have no subject: Leon has no implanted memories to resolve his lack and no photograph of a mother to put his faith in (
‘Let me tell you about my mother…’ he says in his fury). Leon’s photos are so important because they are the only history he will ever have.
Blade Runner consistently uses photography as a device to express the idea that human memory is a fiction. Deckard inserts one of Leon’s snapshots into his Esper machine and it transforms the two-dimensional image into a three-dimensional space he can search. The Esper achieves the impossible because it is not remaking the space, but recalling a memory of that space – remembered by Leon through the photograph. The fantastical nature of the Esper and the discontinuity of the images it produces soon form a critical mass of unreality. The woman Deckard finds hidden in the snapshot and the woman in the hardcopy he prints are visibly not the same woman, and neither one resembles the Replicant woman he eventually retires. Leon’s memory is decaying before our eyes.
In Leon’s snapshot is another coded reference to the artificial or constructed nature of memory. Marshall Deutelbaum has noted the intentional resemblance between the snapshot and “The Arnolfini Marriage” by Jan van Eyck.  The painting attested to the exchange of marriage vows between the depicted couple, and so the artist added the reflection in a convex mirror of two men witnessing the event from the perspective of the viewer. When we look at the painting we see the event from a subjective position, assuming the gaze of the two witnesses reflected in the mirror. The introduction of this simulated reflection reminds us that there is no position from which objective truth can be observed because perception and experience are always subjective. When Deckard looks at the snapshot he is seeing a decaying personal memory, not the evidence of an irrefutable truth. In the first instance the Esper produces imperfect images because Leon remembered imperfectly.
Subsequent detection scenes are haunted by visual and verbal discontinuities, as if the disintegration of memory is causing the disintegration of reality for Deckard. He replays the recording of Leon taking the Voight-Kampf test and the climactic line
‘Let me tell you about my mother…’ now becomes
‘I’ll tell you about my mother…’ When he has the snake scale examined the old woman quotes a serial number that is different from the number seen on the monitor. Devices intended to assist his search for the truth in fact make it more difficult for him to distinguish perception from reality. It is appropriate that Blade Runner is set in the year 2019: for all its imaging technologies this place has less than 20-20 vision.  The sense of paranoia is fostered by giant advertising blimps that loom overhead and offer Deckard the chance to forget the past:
‘The chance to begin a new life…’
Deckard is understandably reluctant to admit his reality crisis – he is a detective and the truth is his business – but the Replicants cannot avoid confronting their identity crisis. Their leader, Roy Batty, is the most willing to embrace his lack of history and seize the freedom to construct his own self-image. While Leon is searching for the comfort of memory to resolve his lack, Roy is forging his identity in the fire of experience. The film speaks the language of memory while we are with Deckard and Rachael, but when we are with Roy it speaks the language of sensation:
‘If you could see what I have seen with your eyes.’ Roy is defined by his capacity for autonomous thought and action, not his capacity for memory recall. When Sebastian asks him to show his prowess he replies:
‘We’re no computers, Sebastian. We’re physical.’
In the spirit of joie de vivre Roy meets his maker to demand more life.
‘You were made as well as we could make you’ he is told by Tyrell,
‘But not to last’ he protests. Accelerated decrepitude afflicts every aspect of this place and the Nexus-6 Replicants are merely its most technologically advanced expression. Roy was conceived as the perfect inhabitant of the terminal city: his amorphous personality thriving in the cultural schizophrenia, his death reflecting the decay of this civilisation.
‘Revel in your time’ Tyrell exhorts. In reply, Roy passionately kisses his creator and then murders him in a fit of primal retribution, but he remembers his father’s words. As Roy descends to earth he glares defiantly at the heavens, revelling in the magnificence of his existence.
When this fallen angel faces the assassin in the final conflict, the atmosphere of creeping anxiety is transformed to one of sudden violent terror. As the pair ascend the rain soaked ruins of the Bradbury, the prey stalks the assassin and the assassin learns how it feels to fight for his life. On the rooftop Deckard leaps a chasm in a desperate act of escape, but he is barely able to cling to the opposite ledge. Roy leaps across in pursuit and stands over his helpless quarry to ask:
‘Quite a thing to live in fear, isn’t it?’ Then at the moment Deckard is about to fall to his death, Roy grabs him and lifts him to safety. The pair sit face to face on the rooftop, and with the last of his life Roy teaches Deckard his lesson:
‘I’ve seen things you people wouldn’t believe. Attack ships on fire off the shoulder of Orion. I watched C-beams glitter in the dark near the Tanhauser Gate. All those moments will be lost in time like tears in rain.’
To live in fear is to live in the moment – is to live for the moment. Roy’s brief existence has been experienced with the heightened senses of an animal acting on instinct and fighting for survival. His struggle for life and liberty has taught him to appreciate every instant, that the past must first be lived if it is to be remembered, that it is not futile to hunger for sensations and gather experiences even if perception is imperfect and even if the memories will disintegrate with time. What is important is not to have seen the truth but to have seen. Deckard absorbs the revelation, exhausted and in shock as he watches Roy die serenely in front of him. The lesson is restated explicitly by Gaff when he arrives at the scene to congratulate Deckard.
‘It’s too bad she won’t live,’ he says of Rachael,
‘but then again, who does?’ In four years the Nexus-6 Replicants have lived more than most humans do in a lifetime.
Deckard goes home, fearful that someone has been sent to retire Rachael. What he is afraid of losing most is not the assurance of his human status nor the integrity of his memories, but the Replicant woman he has fallen in love with. Like the dove Roy Batty releases into an azure sky, Deckard seizes the chance to escape and to make a life with Rachael. In a film that imagines a civilisation obsessed with the past (history, memory, culture) the final subject is not one of origins but of destinations.
‘Where are you going?’ Roy asked of Deckard, and now we see the answer: somewhere, anywhere, the future.