What is one of the questions which most interests Philip K. Dick?
“What constitutes the authentic human being?“

How does Blade Runner address the issue of the authentic human?
Through the speculated existence of replicants and extrapolation therefrom.

What is the significance of the replicants?
The existence of artificial humans which are, on many levels, indistinguishable from real humans forces one to reassess their ideas about what a human is.

What is the Voight-Kampff machine?
Device which measures in an individual the degree of empathic response to carefully worded questions and statements in an individual.

According to the Voight-Kampff machine, what constitutes the authentic human being?
Feelings; emotions; empathy. An inauthentic human demonstrates measurably less compassion and empathetic concern.

Does this definition have precedents?
Early myth (autistic children were once considered the work of demons or faeries who stole the authentic children and replaced them with emotionless doppelgängers), monster stories (Dracula, The Strange Case of Dr. Jekyll & Mr. Hyde, Beowulf), and 1950s science fiction films (The Thing from Another World, Invaders from Mars and Invasion of the Body Snatchers) all postulate that humans have feelings, while non-humans do not.

Why is this definition problematic?
It allows for replicants to be authentic humans and humans to be inauthentic humans: a direct contradiction of conventional thought. This is especially problematic since the definition’s purported purpose is to distinguish between humans and replicants.

What is an example of replicant shown to be authentic human?
Although initially only self interested, Roy Batty, on the brink of his own death, is able to genuinely empathize with Deckard.

Does Roy’s development have precedents?
Roy demonstrates empathy at the end of his four year life. Human children develop a “theory of mind“, the neurological foundation of empathy, around four years of age. Maturity from inauthentic to authentic human can be considered a normal part of human development.

What is an example of human shown to be inauthentic human?
Philip K. Dick discovered diaries by SS men stationed in Poland. One sentence read, “We are kept awake at night by the cries of starving children.” According to Dick, “There is obviously something wrong with the man who wrote that. I later realized that … what we were essentially dealing with was … a mind so emotionally defective that the word ‘human’ could not be applied to them.”

Why does Deckard empathize with the replicants?
One or more of the following: he doubts his ability to distinguish them from humans; he doubts their distinction from humans; he recognizes their developing humanity; he doubts his own humanity; he himself is a replicant; he shares with them an alienation from his fellow humans; through studying and dispatching them he has come to understand them better than he does his fellow humans; Deckard does not empathize with the replicants.

What use, if not to identify replicants, is the Voight-Kampff definition of the authentic human?
To distinguish friendly from hostile. Frankenstein’s monster sought a place in society among humanity; Dracula sought only to prey on it. Frankenstein’s monster could have become an equal member of society, Dracula could only be a utilitarian tool of society—if he could be controlled—or an enemy, if he could not.