Dark City asks the questions, who are we without our memories and how are our souls involved? Are our memories and our souls intertwined? If you remove the memories, do you render people soulless and identity-less? Dark City is controlled by aliens called The Strangers who want to know the answers to these questions. As we find out along the way, they have created a world and populated it with a group of human beings in order to experiment on and to study them. Their civilization is dying and they need to understand what it is in humanity that makes humans survivors. The city is perpetually dark because they cannot tolerate sunlight. They wear the bodies of dead humans as their own, giving them a vampiric appearance (they reminded me of Nosferatu at times--tall, thin, white entities floating in the air). Their civilization is defined by collective memory, where no individual has his own private memories. Collective memories are what each of them experience, so they have no individuality, no soul. They mistakenly believe that the soul is found in men's minds that hold their memories, so they create experiments with the help of a neurological scientist, Daniel Schreber (played by Kiefer Sutherland), to remove the individual memories from the brains of each human being and to imprint their brains with new memories that are concocted by the scientist following the orders of the Strangers. This naturally leads to a sort of chaos in the city, as people can wake from one day to the next and not remember who they were or what they did yesterday. They no longer know who they are. But one man, the main character John Murdoch (played by Rufus Sewell) has not been imprinted completely; he awoke while he was being imprinted and he begins a quest to find out who he is/was based on the flashes of memory that plague him. What he knows is that he is not a serial killer of prostitutes, as his imprinting has told him he is. Unfortunately the imprinting of individuals is leading to collective memory in the humans; they have begun to forget who they are. It is almost impossible to fight against the Strangers because a person never knows when he or she will be picked out of the crowd to be imprinted. But John Murdoch decides to fight the Strangers with the help of his wife Emma (played by Jennifer Connelly), a police officer, Frank Bumstead (played by William Hurt), and Daniel Schreber who wants to end the experiments. They succeed in finding out what Dark City really is and about the experiment in which they are involved. In doing so, they destroy the community of the Strangers. The movie is quite good, even though it deals with an extremely complex topic. But sci-fi is allowed to do that--to entertain us and to create questions that perhaps cannot be answered (in our time).
In the first movie, it is the individual memories of Susan and Edward that define who they are and their very different lives in the present. Both suffer but in different ways. Susan's husband betrays her as she betrayed Edward; Edward writes a novel to help him deal with the crushing memories of her betrayal. In the second movie, the idea of collective memory negates individual memory. Individual memories would eventually become part of the collective memory and humans would cease to feel and to be human. There would be no need for revenge, guilt, sorrow, or forgiveness, because all individual memories would be erased for the good of the whole. This is what the society of Strangers has misunderstood. Our physical (chemical neurological) memories may be found in our brains, but all facets of memory are not. They are also found in our hearts and souls and are probably a very complicated and hitherto inexplicable combination of all three.
We are who we are as a result of the memories that we have built up and stored over time. Is that buildup orderly and coherent? Does the brain control the storage of memory in an orderly fashion? How the brain stores memories › Friedrich-Alexander-Universität Erlangen-Nürnberg (fau.eu). All the more terrifying to contemplate what dementia patients experience on their gradual downward progression toward oblivion. Without coherent memory, we lose our 'selves', our individuality, our identity. This is not to say that memories have died in dementia patients, just that their disease has tangled and fragmented them, and in doing so, has fragmented their lives. Over time, the brain cells atrophy. There is much to be learned about memories and how they are created, stored, and retrieved in the brain. But all facets of memory cannot be explained by the brain alone.