This movie is not a thriller. It tells a very very very sad story.

Rating: 9/10 (20 March 2010)

Teddy Daniels was a soldier and he witnessed the dead bodies of Jews in the death camp, and he also killed many German soldiers out of hared. He was deeply mentally traumatized by what he saw and what he did during the war and this was implied by the lines in the movie when Teddy first met Dr. Cawley and asked about Solando Rachel's husband(Teddy) and Dr. Cawley said "He died. On the beach of Normandy. She is a poor widow." After the war Teddy came back to Dolores Chanal but started drinking because of the war trauma. He also ignored Dolores' mental problem partially because that he loved her so much that he didn't want to put her in a mental institution and partially because of his drinking problem. His ignorance finally led to Dolores drowning their three kids and his killing of Dolores. He couldn't face the reality so he was sent to the Shutter Island where Dr. Cawley was working on a more humane project(role-playing) on curing mentally-challenged patients and Teddy was chosen as the subject. Because Teddy didn't accept the reality so he thought that he was somebody else. He hated himself so much that he imagined Laeddis,his wife's killer(himself), as a very ugly man. The movie also explained that why he didn't kill himself---he saw the German officer was in great pain after he didn't commit a successful suicide. And the other reason could be that he didn't believe his wife was dead and he couldn't let her go. Two scenes truly saddened me: one is in the apartment when Teddy holds his wife but she is burning away; the other one is when Teddy found out his wife drowned their kids and shot her.
At the end of the movie, I believe that Teddy was cured(he was cured before but regressed), however he still couldn't face the truth so he chose to go to the lighthouse. Dr.Cawley's method works but it just didn't work on Teddy. I think the movie presents us a question: can we save humanity?