The film operates on multiple dramatic and narrative levels. It employs some of the conventions of film noir, among them the character of a femme fatale; narration by the protagonist (in the original release); chiaroscuro cinematography; and giving the hero a questionable moral outlook – extended to include reflections upon the nature of his own humanity.[114][115] It is a literate science fiction film, thematically enfolding the philosophy of religion and moral implications of human mastery of genetic engineering in the context of classical Greek drama and hubris.[116] It also draws on Biblical images, such as Noah's flood,[117] and literary sources, such as Frankenstein[118] and William Blake.[119] Although Scott said any similarity was merely coincidental,[120] fans claimed that the chess game between Sebastian and Tyrell was based on the famous Immortal Game of 1851.[121]
Blade Runner delves into the effects of technology on the environment and society by reaching to the past, using literature, religious symbolism, classical dramatic themes, and film noir techniques. This tension between past, present, and future is represented in the "retrofitted" future depicted in the film, one which is high-tech and gleaming in places but decayed and outdated elsewhere. In an interview with The Observer in 2002, director Ridley Scott described the film as "extremely dark, both literally and metaphorically, with an oddly masochistic feel". He also said that he "liked the idea of exploring pain" in the wake of his brother's death: "When he was ill, I used to go and visit him in London, and that was really traumatic for me."[122]
A sense of foreboding and paranoia pervades the world of the film: corporate power looms large; the police seem omnipresent; vehicle and warning lights probe into buildings; and the consequences of huge biomedical power over the individual are explored – especially regarding replicants' implanted memories. The film depicts a world post ecocide, where warfare and capitalism have led to destruction of 'normal' ecological systems.[123][124] Control over the environment is exercised on a vast scale, and goes hand in hand with the absence of any natural life; for example, artificial animals stand in for their extinct predecessors.[125] This oppressive backdrop explains the frequently referenced migration of humans to "off-world" (extraterrestrial) colonies. Eyes are a recurring motif, as are manipulated images, calling into question the nature of reality and our ability to accurately perceive and remember it.[126][127] The film also consists of themes of Japan as a power, coming amid a time of Anti-Japanese sentiment in the United States.[128]
These thematic elements provide an atmosphere of uncertainty for Blade Runner's central theme of examining humanity. In order to discover replicants, an empathy test is used, with a number of its questions focused on the treatment of animals – seemingly an essential indicator of one's "humanity". Replicants will not respond the same way humans would, showing a lack of concern. The film goes so far as to question if Deckard might be a replicant, in the process asking the audience to re-evaluate what it means to be human.[129]
The question of whether Deckard is intended to be a human or a replicant has been an ongoing controversy since the film's release.[130][131] Both Michael Deeley and Harrison Ford wanted Deckard to be human, while Hampton Fancher preferred ambiguity.[132] Ridley Scott has stated that in his vision, Deckard is a replicant.[133][134] Deckard's unicorn-dream sequence, inserted into Scott's Director's Cut and concomitant with Gaff's parting gift of an origami unicorn, is seen by many as showing that Deckard is a replicant – because Gaff could have retrieved Deckard's implanted memories.[118][135][136] The interpretation that Deckard is a replicant is challenged by others who believe the unicorn imagery shows that the characters, whether human or replicant, share the same dreams and recognize their affinity,[137] or that the absence of a decisive answer is crucial to the film's main theme.[138] The film's inherent ambiguity and uncertainty, as well as its textual richness, have permitted multiple interpretations.[139]
