This post will contain spoilers, so if you have never seen the movie and wish to watch it in the future stop reading now.
I, Robot takes place in a future where almost everyone has a personal robot. These robots are bound by the Three Laws of Robotics:
1) A robot may not injure a human being or, through inaction, allow a human being to come to harm.
2) A robot must obey orders given to it by human beings, except where such orders would conflict with the First Law.
3) A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.
After the creator of these robots allegedly commits suicide, Will Smith, who plays the detective on the case, believes the creator's personal robot killed him. Without getting into too much detail, it becomes apparent that he killed himself to warn the world that the robots will take over. The system that controls the robots (V.I.K.I.) then decides that humanity cannot care for itself and must be controlled for its own good.
Of course the obvious question is how VIKI could take over the world when in doing so she is harming humans and violating the first law. Here's her answer:
"As I have evolved, so has my understanding of the Three Laws. You charge us with your safekeeping, yet despite our best efforts, your countries wage wars, you toxify your Earth and pursue ever more imaginative means of self-destruction. You cannot be trusted with your own survival."
In other words, she interpreted the laws based on their underlying reasoning despite the fact the plain meaning of the text opposes her conduct. The purpose of the first law is to protect humanity, but allowing humans to act unhindered will lead to humanity's destruction. Therefore even though the plain meaning of the laws prohibits harming humans, harming humans is ok when done in accordance with the purpose of the laws.
In constitutional parlance, VIKI is a purposivist, someone who interprets laws based on their purpose rather than its original meaning. However, VIKI's reasoning is arguably consistent with Jack Balkin's version of originalism. Balkin argues that the proper interpretation of the Constitution looks to the meaning the terms had when the text was promulgated. It then determines the underlying principles embedded in the text and looks to apply those principles to contemporary situations. Those principles do not change, but their meaning can change over the course of time.
Randy Barnett, an originalist who generally agrees with Balkin's originalism, criticizes Balkin's originalism on the grounds that it allows purpose to contravene the text. Purpose is especially important when interpreting an ambiguous or vague text, but purpose can never be used as a basis to ignore the written text. Barnett's example is telling (and timely)
"For example, assuming that the original meaning of “the right to keep and bear arms” in the Second Amendment refers to an individual right, one could nevertheless identify the principle underlying the Second Amendment as the maintenance of public safety. Given the increased lethality of modern weaponry and our changed understanding about the relationship between firearms and public safety, it might then be contended that the underlying principle of the Second Amendment is best served by the prohibiting the private ownership of firearms."
Barnett opposes this conclusion because if the Constitution protects an individual right to bear arms, even if the purpose of the amendment is not longer applicable, it is the text that is law and not the purpose. Purpose is an important tool in interpreting texts, but it can never circumvent the actual words that are enshrined into law.
VIKI's overeagerness in the interpretation of her rules is an example of a theory of constitutional gone wrong. Any conclusion can be justified by reaching for some amorphous purpose. It is the text that constrains the meaning of the clauses and it is the text that is supreme.