To Truly Find What You Want, You Have to Find What You Are.
The most integral part of immortality is identity. If identity is compromised, then we, as we know ourselves, cease to be. When closely examined, the definition of identity becomes somewhat abstract. Identity can be defined in many different ways. Both subjective (internal) and objective (external) are the combined to establish one’s identity. The dominating perspective is one which is the thought of the self and how it interacts with the rest of the world. With technologies that are increasingly able to replace human body parts, including those of the brain, we must solve problems of identity before applying these techniques. As the trans-humanist (slowly replacing anatomy with machines) movement gains momentum, and after a few thought experiments, you might want to think twice about downloading your consciousness to the internet.
While the notion of identity might not mystify the mind at first glance, the idea of has been challenged throughout human history, first by philosophers, later by scientists. Here are some of their concerns:
Ship of Theseus
“Theseus’ paradox” was a thought experiment proposed by ancient Greek philosopher Plutarch. He proposes the idea of a ship. One that needs occasional replacement parts and maintenance. Parts that are replaced are exact replicas of the originals. While an observer may not notice a difference, the ship is gradually replaced piece by piece until the every original part is replaced. The observer might then wonder, “is this the same ship?”
In fact, scientists have known since the 1950s that many of the the atoms in a human body are replaced every year. Because of the process that a cell goes through when it metabolizes energy (energy in, waste out), all of the atoms in the body are eventually replaced.
This thought experiment might lead one to believe that the self relies primarily on the preservation of information. So long as you have the blueprint to the ship and an endless amount of supplies, it is essentially immortal.
The Teletransportation Paradox
Two millennium later, a philosopher named David Parfit proposed a counter thought experiment to again challenge identity. Imagine you are in a futuristic society, one that has developed the technology to teleport individuals around the Earth and Mars. You yourself have never used the device, but you have spoken to close friends and family who have. They urge you to come visit them and experience the different and strange red planet. One day you decide to go. You step into a machine guided by a technician, followed by a quick and painless scan of your body. The technician then informs you that the process is complete. There is now a copy of yourself enjoying good company on Mars. Your body on Earth is destroyed after confirming the copying process on Mars has been successful. Have you actually been transported, or were you merely copied and deleted?
Parfit’s experiment demonstrates why we feel the need for psychological continuity. Theseus’s ship and Parfit’s teletransportation paradox leave the mind in a confusing predicament.
Identity may be just an idea, a placeholder to help describe and communicate our experiences as we perceive them. Like a photograph, facts about identity are only definable in the moment in which they are taken. As a matter of conscious experience, the self is defined by a particular moment of reflection, at a particular time, in a particular place, and in a particular mind-state. The idea of the self, though seemingly permanent and unchangeable like Theseus’ ship, changes over time and circumstance. The brain physically changes with every new experience. It makes new connections, rewires itself, and deteriorates with age and injury. Perhaps identity is an illusion, one commonly adhered to in order to make sense of the world. It is even possible to imagine substantial differences between identity and subjectivity or consciousness as the latter able to ever change while the former always rigid. Arguments like these will shake the foundation of who we think we are and what we think we want for our future.