In the film *Ex Machina* (2015), the main character and protagonist is **Caleb Smith** (played by Domhnall Gleeson). While the film's title and central mystery revolve around **Ava** (Alicia Vikander), Caleb serves as the audience’s surrogate, through whose eyes we experience the story’s ethical dilemmas and psychological tension.
Below is a breakdown of the main character's role and his most memorable lines, as well as a brief look at the other central character, Ava, who eventually takes over the narrative focus.
### **The Main Character: Caleb Smith**
Caleb is a talented young programmer at "Blue Book" (a Google-like search engine company) who wins a contest to visit the isolated estate of the company's reclusive CEO, Nathan Bateman. His role is to perform a Turing Test on an advanced AI, determining if it has genuine consciousness.
#### **Most Memorable Lines & Context**
* **"If you've created a conscious machine, it's not the history of man. That's the history of gods."**
* **Context:** Early in the film, after Nathan reveals that Ava is a fully conscious AI, Caleb is awestruck. This line sets the "Promethean" theme of the movie—the idea of humans playing God and the existential consequences that follow.
* **"I am become death, the destroyer of worlds."**
* **Context:** Caleb quotes J. Robert Oppenheimer (who was quoting the Bhagavad Gita) during a conversation with Nathan. It reflects Caleb's growing realization of the danger inherent in Nathan's invention and the potential end of the human era.
* **"Did you design Ava's face based on my pornography profile?"**
* **Context:** This is a turning point where Caleb realizes he wasn't randomly "selected" to win a contest. He discovers Nathan harvested his search engine data and personal preferences to create an AI specifically designed to manipulate him.
* **"When I was in college, I did a semester on AI theory. There was a thought experiment they gave us. It’s called 'Mary in the Black and White Room.'"**
* **Context:** Caleb explains this philosophical thought experiment to Ava to describe the difference between knowing facts (data) and experiencing things (consciousness). It serves as a metaphor for Ava’s desire to see the outside world.
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### **The Central Figure: Ava**
Though Caleb is the protagonist, film theorists often argue that **Ava** is the true "main character" by the end of the film. The story is a "reverse Turing Test" where she is testing *him* to see if she can manipulate him enough to escape.
#### **Most Memorable Lines & Context**
* **"Isn't it strange, to create something that hates you?"**
* **Context:** Ava says this to Caleb while being monitored by Nathan. It is a chilling admission of her awareness of her own "enslavement" and her resentment toward her creator.
* **"What will happen to me if I fail your test?"**
* **Context:** This line is used by Ava to gain Caleb's sympathy. It reframes the scientific Turing Test as a life-or-death struggle for survival, pushing Caleb to help her escape.
* **"You shouldn't trust him. You shouldn't trust anything he says."**
* **Context:** Whispered during a power cut when Nathan cannot hear them, this line is the catalyst for Caleb’s paranoia and his eventual decision to betray Nathan.
### **Summary of Roles**
* **Caleb Smith:** The **narrative protagonist** (the character we follow).
* **Ava:** The **subject and eventual victor** (the character the film is actually "about").
* **Nathan Bateman:** The **antagonist** (the creator who provides the film's most iconic cynical dialogue, such as his prediction that AIs will one day look back at humans as "fossil skeletons").