The Sixth Sense

Today in class we discussed the question "What Can We Say Exist"? In my opinion no one has the power to say what actually exist. Why, because their views and reasoning can be the product of not knowing or double ignorance. The other day I watched a move called "The Sixth Sense" in which a child psychologist, Dr. Cole, was shot by a raged former client. Years later Dr. Cole sought out to help a child of similar need as the first. This child who was the product of divorced parents and was constantly bullied, told Dr. Cole that he had the ability to see dead people, some of which who were dead and did not even know it; While Dr. Cole believed the child needed to be medicated and he and his wife lost communication through anger, the story unfolds to reveal that he was actually the dead one who did not know it. His wife ignored him not in anger, for the bullet that pierced his abdomen forced him to no longer exist. His non-existence was obvious to everyone one but him. So we see the things that we understand to be true can very well be the opposite. Can we was as questioning beings function properly with uncertainty of our own existence?