From the black-and-white photo, a girl with bows is looking at me attentively. This is my photo. Since then, my height, weight, facial features, interests, knowledge and habits have changed. Even the molecules in all the cells of the body managed to completely change several times. And yet I am sure that the girl with bows in the photo and the adult woman holding the photo in her hands are the same person. How is this possible?
This riddle in philosophy is called the problem of personal identity. It was first formulated explicitly by the English philosopher John Locke. In the XNUMXth century, when Locke wrote his writings, it was believed that man is a «substance» — this is the word philosophers call that which can exist by itself. The question was only what kind of substance is it — material or non-material? Mortal body or immortal soul?
Locke thought the question was wrong. The matter of the body changes all the time — how can it be a guarantee of identity? No one has seen and will not see the soul — after all, it is, by definition, non-material and does not lend itself to scientific research. How do we know if our soul is the same or not?
To help the reader see the problem differently, Locke made up a story.
Personality and character traits depend on the brain. His injuries and illnesses lead to the loss of personal qualities.
Imagine that a certain prince wakes up one day and is surprised to find that he is in the body of a shoemaker. If the prince has retained all his memories and habits from his previous life in the palace, where he may well no longer be allowed in, we will consider him the same person, despite the change that has occurred.
Personal identity, according to Locke, is the continuity of memory and character over time.
Since the XNUMXth century, science has taken a huge step forward. Now we know that personality and character traits depend on the brain. His injuries and illnesses lead to the loss of personal qualities, and pills and drugs, affecting the functioning of the brain, affect our perception and behavior.
Does this mean that the problem of personal identity is solved? Another English philosopher, our contemporary Derek Parfit, does not think so. He came up with a different story.
Not a very distant future. Scientists have invented teleportation. The recipe is simple: at the starting point, a person enters a booth where the scanner records information about the position of each atom of his body. After scanning, the body is destroyed. Then this information is transmitted by radio to the receiving booth, where exactly the same body is assembled from improvised materials. The traveler feels only that he enters a cabin on Earth, loses consciousness for a second and comes to his senses already on Mars.
At first, people are afraid to teleport. But there are enthusiasts who are ready to try. When they arrive at their destination, they report every time that the trip went great — it’s much more convenient and cheaper than traditional spaceships. In society, the opinion is taking root that a person is just information.
Personal identity over time may not be all that important — what matters is that what we value and love continues to exist.
But one day it crashes. When Derek Parfit presses the button in the teleporter booth, his body is properly scanned and the information is sent to Mars. However, after being scanned, Parfit’s body is not destroyed, but remains on Earth. An earthling Parfit comes out of the cabin and learns about the trouble that happened to him.
Parfit the earthling does not have time to get used to the idea that he has a double, as he receives new unpleasant news — during the scan, his body was damaged. He is to die soon. Parfit the earthling is horrified. What does it matter to him that Parfit the Martian remains alive!
However, we need to talk. They go on video call, Parfit the Martian comforts Parfit the Earthman, promising that he will live his life as they both planned in the past, will love their wife, raise children and write a book. At the end of the conversation, Parfit the Earthman is a little comforted, although he still cannot understand how he and this man on Mars, even if indistinguishable from him in nothing, can be the same person?
What is the moral of this story? The Parfit philosopher who wrote it suggests that identity over time may not be all that important—what matters is that what we value and love continues to exist. So that there is someone to raise our children the way we wanted it, and to finish our book.
Materialistic philosophers may conclude that the identity of the person is, after all, the identity of the body. And supporters of the information theory of personality may conclude that the main thing is the observance of safety precautions.
The position of the materialists is closer to me, but here, as in any philosophical dispute, each of the positions has the right to exist. Because it is based on what has not yet been agreed upon. And that, nevertheless, cannot leave us indifferent.