The film Shutter Island makes the audience ponder the philosophical concept of knowledge and, more specifically, makes us question how we know what we know.
It is set on an isolated island with a large mental hospital for the criminally insane where the main character, Edward Daniels, has been supposedly brought to find an escaped patient. The story slowly unravels, revealing, by the end, that he himself has been a patient there for the last two years and everything we have seen and experienced through his perspective has been an illusion, leading us to the first philosophical idea: Cartesian skepticism.
Descartes identified that we perceive the entire world through our senses; however, our senses may well be giving us incorrect information, as was Edward Daniels’ case, so most of our knowledge is fundamentally flawed.
Descartes suggests several reasons as to why we can’t rely on our senses; we might be dreaming, insane, under the influence, or tricked by a demon, all of which were covered throughout the film, demonstrating the sophistication and depth to which the overall idea was explored.
Teddy Daniels begins to have disturbing dreams and vivid hallucinations under the influence of narcotics, even going so far as climbing cliffs to have conversations with false people that even the audience are led to believe are real at the time. While he hasn’t been tricked by a ‘demon’, Dr Rawley has set up an elaborate plan to make him believe his delusions of being a US marshal.
He begins to question out loud in his dreams, “Are you real?”, conveying the lack of trust that can be placed on our senses even within ourselves.
There are several limitations as well to how Cartesian skepticism is explored, including its lack of engagement with the major question surrounding Cartesian skepticism. The film focuses on how certainty in knowledge can be achieved, demonstrated through Teddy Daniels’ quest to discover the truth. This takes away from the real issue highlighted in Cartesian skepticism, which is whether certain knowledge can be attained at all.
Locke’s idea of tabula rasa, meaning the idea that humans are born with a blank slate and everything we learn is experienced through our senses, is also explored throughout the film.
Teddy Daniels believes he was a US war veteran, but, as the story progresses, it becomes evident that his memories have been manipulated and reconstructed by his mind. This aligns with Locke’s view that our knowledge and sense of self is formed through sensory experiences; however, the film focuses on the effects of insanity and traumatic events and how they blur the line between reality and delusions.
It still doesn’t solve the problem that this theory only works if you begin with a rational mind. Locke proposes that we can gain certain knowledge through trusting our sensory experiences, but he doesn’t account for people who are mentally unstable, such as Teddy Daniels.
Coherentism is the idea that a belief is justified if it fits in with our other beliefs. This is perhaps the most relied upon theory of justification for Teddy Daniels, as he believes his hallucinations and dreams based solely on the fact that they make sense with relation to the other things he wants to believe about the island.
For example, he meets an enigma, who he believes to be the escaped patient, who tells him he needs to escape, and the workers do perform dangerous psychosurgery. He immediately believes this as it fits in with his preconceived ideas about the island, only to later find he was wrong and would have been better off believing Dr Rawley and the officials.
This demonstrates the convenience of coherentism, a theory that we tend to subconsciously use as it requires too much effort to fact-check every statement we are told. However, it also conveys issues with coherentism as this concept relies on first having a rational mind to string plausible ideas together and separate them from doubtful ones, based on your surrounding knowledge.
As Teddy was insane, he was unable to correctly critically analyse all the information he was fed, leading him to believe complete delusions.
The film, however, fails to address another limitation with using coherentism, which is that it doesn’t work if you don’t have any previous knowledge on the subject. The film tries to explain Teddy’s ‘going off the rails’ by his insanity, but a large portion would be due to his lack of previous knowledge about Shutter Island that he can rely on to distinguish between incorrect and correct information.