What is a Replicant?
According to the inter-title in the beginning of Blade Runner, a replicant is a robot designed by the Tyrell Corporation that is "virtually identical to a human". The Tyrell Corporation's top of the line are the Nexus 6 replicants which are "superior in strength and agility, and at least equal in intelligence, to the gentic engineers who created them." The only way to tell a replicant apart from a human is their lack of emotional responses, which is measured by the Voight-Kampff test. The Nexus 6 models were used primarily as slavelabor in the offworld colonies. After a "bloody mutiny," they were banned from being on earth upon penalty of death. The term used for the executions of these replicants is retirement. This is an interesting twist; as emotions are so valued, the humans take away any emotional connotation linked to killing the replicants.
Rachael
Rachael was the latest experiment of the Tyrell Corporation. The Tyrell Corporation developed Rachael in order to see if "pillowing" the Nexus 6 model's growing pattern of developing emotions with memories would aid in the Nexus 6s controlling their emotional states. The ultimate goal was to make emotionally stable Nexus 6s who are easier to control than their undeveloped siblings. Rachael does not know her true identity because she was "gifted" the memories of Tyrell's niece and once she discovers the truth, she continually questions the system, especially Deckard, that condemns her as non-human.
Roy Batty
Roy Batty is the leader of the errant Nexus 6's. He is the most philosophical and conflicted character of the film. Roy is just beginning to realize his own mortality, emerging love, and a hatred for his maker; all in a matter of days. Roy Batty is seen as a mostly Satanic figure, especially when he interrogates Chew, the replicant's eye-maker, and he quotes William Blake: "Fiery the angels fell/ deep thunder rolled from their shores/ Burning with the fires of Orc" (3). But some interpret the ending as a redemption for Roy, and he laments "I've seen things you people wouldn't believe. Attack ships on fire off the shoulder of Orion. I've watched c-beams glitter in the dark near the Tannhäuser Gate. All those ... moments will be lost in time, like tears...in rain. Time to die" (3).
Deckard?
In the original print and the theatrical version, Deckard's humanity isn't questioned. However, in the directors release and to an extent the Final cut, Deckard's humanity is suspect. The first scene used to prove Deckard is a replicant is when Deckard is musing over the photographs and then there is a cut to a scene of a Unicorn running and then we cut back to Deckard who's had a moment of inspiration.
In the clip below we see another way Scott depicts Deckard as a possible replicant. We can see with Rachael and Deckard's glowing eyes, an excellent use of lighting in Blade Runner, that Scott is trying to emphases their otherness.
In this final clip we can see the damning evidence of Gaff's origami unicorn. Shown not only to us but to Deckard too, that his thoughts and memories aren't his own. The implication seems to link Deckard's mythic fantasy sequence (involving a unicorn) with the notion that his supposedly "private" moments are, in fact, accessible by the powers that be (Gaff being a emissary of sorts).
The ambiguity concerning Deckard's identity (but also the existence of replicants in the first place) positions the question of "why" as a logical extension of the "what" that defines a replicant. The human characters in the film seems dearly invested in maintaining a clear definition of difference between humanity and the replicant population. As mentioned previously, the film notes in the opening inter-title that replicants are "virtually identical to humans", making the difference one of a supposed lack of empathy on the part of the replicated. In short, the replicants in the film, who are rebels in their claim to the safeguard of emotional experience that previously signified a uniquely human conception of selfhood, are a threat to the foundations of humanity's essential ties to themselves. Roy Batty is troubling not only because he kills people, but because he is a disruption to the social construction (and Deckard's as well) of identity. The film is very much aware of this tension, and exploits in the way it uses the aforementioned visual signs of "replicant-ness" to make some sort of difference known, and also question the validity of such a seperation.
Work Cited
1. "Replicant" wikipedia.org, 20 Oct. 2009. Web. 17 Nov. 2009.
2. "Blade Runner Riddle Solved" BBC News, 9 July. 2009. Web. 17 Nov. 2009.
3. "Blade Runner" wikiquote.org, 27 Oct. 2009. Web. 17 Nov. 2009.