Ex Machina takes its name from the phrase “Deus ex machina” (pronounced with a “k” not a “ch” sound). Used in ancient Greek theatre, it literally translates “God from the machine.” The film plays with the concepts of what a god is, what a machine is, how these concepts relate to our humanity and ultimately what that means for whoever is in control of the situation.
As the film opens, Caleb (Domhnall Gleeson), a programmer at a Googlesque search engine company, has won the opportunity to spend a week with the company's founder Nathan (Oscar Isaac) at his secluded residence. Upon arrival, Caleb discovers that his prize vacation will be different than he had planned. After confessing that his home is also a top secret research facility and making Caleb sign an ironclad non-disclosure agreement, Nathan gives him a key-card with access to all the rooms in his home, excepting a few. Nathan explains that he has been using much of his wealth to research artificial intelligence (AI) and that he has brought Caleb there to perform a type of “Turing Test,” a classic test of artificial intelligence systems that is deemed passed if a human can not accurately determine whether they are communicating with a human or a machine. The twist with this test is that Ava (Alicia Vikander), Nathan's AI, is quite obviously a machine, and Nathan wants Caleb to determine whether “she” truly has consciousness or a soul.
Early in their discussions about AI, Caleb and Nathan discuss what the criteria of his test should be and mention an early classic type of AI, the chess playing computer. They decide that it cannot be truly said to be conscious because it isn't aware that it's playing a game. So the question in regards to Ava is, “Does she know that she's playing chess?” From that point the film becomes a mental game of chess that keeps you guessing about who holds the advantage.
An added wrinkle to the mental chess game being played is Ava's sexuality. The AI that Caleb is evaluating is very much embodied as female. When Caleb questions Nathan about this and asks Nathan if he programmed Ava to “like” him, Nathan insists that sexuality is a component of human intelligence and therefore an appropriate component of a fully fleshed AI. The fact that Ava's sexuality has an effect on Caleb's objectivity is clear.
The character of Nathan functions as a metaphorical mad god, obsessed with his own power and ideas. It is obvious that he feels creating an intelligence as sophisticated as Ava has elevated his status. His godhood has come as a result of the machine he has created. Through most of the film his actions are that of a petulant, loose canon. He drinks to excess and, while claiming to want to be “friends” with Caleb, does everything to make sure he remains in control. He as much as admits that he wants get into Caleb’s head when he claims “I'm Kirk, your head's the Warp Drive, Engage intellect.”
The film is structured around a number of “sessions” during which Caleb conducts his test of Ava. Even before their first meeting literal cracks appear, suggesting that everything is not as it seems. As Caleb questions her, Ava herself questions the validity of the test when she asks “what happens if I don't pass your test?” and after Caleb claims it's not up to him, she responds “why is it up to anyone?” In a later session she playfully turns the tables on Caleb by questioning him and asking “Are you a good person?” It's an interaction that basically asks, “does anyone have the right to determine your value and whether you qualify as sufficiently ‘human?’” As the sessions progress, Ava becomes more human in behaviour, but also visually as more of her mechanical parts are covered with a wig and clothing. The first suggestion that she might be more than either Nathan or Caleb expects is when during a session she admits to Caleb that she has the ability to cause the home's power to temporarily surge and shut down the cameras that Nathan is using to view and record the session. During one of these shutdowns mid-session she warns Caleb that Nathan is not to be trusted. The audience is left to wonder if she's genuine, or playing a game.
Ex Machina clearly has much to say on how humans view themselves as creative beings and how we view that power in relationship to others, especially those we might consider less human, and to God.