For example, a person might interpret an impression of something completely different from someone else. David Hume believes that nobody has a personal identity. Instead, he believes that each person is made up of his or her own self-impressions. Hume believes a persons self-impression is acquired either by someone else or by that persons own idea of his or herself. If you were to ask a random person who he or she is, you would most likely get an answer that would involve some kind of impression or idea that the person has grown up hearing or believing. Furthermore, it is the way that a certain person perceives these self-inflicted impressions that makes him who he or she is.
It is these perceptions and mental thought processes that make Doug Quail the same person he was in the beginning of the story. The main character of the story, Doug Quail, starts out in life as a secret agent/assassin who works undercover for the government on Mars. After he has completed his mission and carried out the duty of killing some person on Mars, Doug Quail returns home to Earth and has his memory erased so that no information of his mission can be released. After his mind has been cleared, and he no longer has the memories of Mars, the government replaces his thoughts and, subsequently, Quail becomes an office worker. Married to his wife and working at his boring desk job, Quail begins to desire and dream of going to Mars.
However, he has no idea that he has ever been there before. Because Doug Quail is poor, in order for him to obtain his desire to go to Mars he must undergo a form of futuristic surgery. When the surgery is completed it will make him honestly believe he traveled to Mars. It is not until after the surgery that Doug Quail begins to vaguely remember his past experience on Mars. The idea of erasing a persons memory for security reasons and having that certain person live a different lifestyle from what he or she was accustomed to living raises a philosophical problem.
Doug Quail seems to be a completely different person because he is no longer the exciting secret agent/assassin that he once was. Therefore, Humes reasoning which states, a persons idea of something or oneself is merely a copy of an impression he or she once had, would make it seemingly obvious that Doug Quail is no longer the person he once was. However, it is not the impressions that make Doug Quail who he is, but it is the way in which he perceives his impressions that make him the same person he was in the beginning. Doug Quails desire and dream of going to Mars was what lay deep within him and how he perceived himself. The government tried to erase Doug Quails memories but was unsuccessful because he still desired and dreamed of traveling to Mars.
For example, if Doug Quail had not continued to desire to travel to Mars after he had his memory erased, yet he desired to be the best office worker he could be, then his identity would have been changed. However, the fascination Doug Quail had with traveling to Mars staid with him long after his memory had been erased. This proves a persons perception of his/herself makes up his or her identity. Hume is correct in saying a persons idea of himself/herself is related to the impressions he or she has of his self or herself. However, a persons real identity lies within the way a person perceives the impressions and not the impression alone.
One might ask, how you perceive an impression? Hume claims that no one has a personal identity unless you are able to see yourself as an abstract object. Further more, Hume believes that all ideas come from impressions, and a person has no ideas unless that person has an impression. He believes that once you have impressions