Ship of Theseus - Philosophy of Identity
The gist of the story: Say we were to preserve Theseus' ship. As parts deteriorated and rotted away, we replace them with new (better/stronger) parts. Eventually, we replace each part with a new one. The question now is - Is it still the same ship? I'm willing to bet most of you will say yes.
Now lets say that instead of replacing the ships components with new ones - we take all of the parts from the warehouse (where the parts are being stored) and reconstruct the ship from these new/better parts. Which ship has the "identity" of Theseus' ship? This is an interesting question because I'm again willing to bet that the "first" ship mentioned is your answer. But why? The parts would have gone to the "first" ship if not into the "second" ship. Why should this be different?
We take Theseus' ship and we tear it completely down in dry dock. In its place, we reconstruct using new parts. Is it still Theseus' ship?
Now lets look at a digital device - my laptop for instance. Let us say that I have an "identical" machine (spec wise) and I cut and paste each file from this hard disk to the "new" machine. Does this "new" machine take the "identity" of the "old?" Can we say this "new" laptop (ship) is in fact Theseus' laptop? Talking with my colleagues - their answer (unanimously) was no - it is not the same.
So here is where I get to the human side of things... Biological process have our bodies continuously replicating cells. In about a year, roughly 90% of the cells in your body will die. But no worries - they are continuously replaced with new ones. So, does that mean we are a different person compared to 12 months ago (I've read this question from several sources)? How about amputees? Today, prosthetic limbs can allow them to do what many of us choose not to do - run marathons. Are they any less of what they were before? <-- I know that sounds "wrong" - put put "political correctness" aside (but by no means am I putting down the situation of an amputee).
Again, I'm willing to bet many will say yes - we're the same person. One argument is that our memories make our "identity." Fair enough. Now lets entertain the future. We now have the technology to save your memories digitally. We can digitize the human brain preserving its intelligence and thinking ability. Just entertain this idea for a few minutes. So if my brain (and its memories) are now digital and I copy it to another vessel. Is it still me? Do "I" still have the same identity? I'd like to think yes, but what was your answer about copying a laptop's memory (was it no - they are not the same)? Why should my digitized memories be any different than that of a laptop's digitized memory?
At this point, my colleagues were floored. They figured out where I was going a few sentences before I said it. That's what makes the topic so interesting (in my opinion).
If anyone has ever heard of HAL-5 - you already know what a feat it is. HAL-5 (yes, that's a play off of a space odyssey) is a human exoskeleton designed to assist those whom otherwise would be unable to walk for long periods of time. The user can lift heavy weights (80kg - say a dishwasher) among other helpful tasks. How does it know to move? Sensors on the skin detect electrical impulses in the brain that tell the muscle to react. Those signals are processed and turned into mechanical motion. All of this happens before the muscles have time to move. That is, the machine is moving before you even do.
So if we replace our bodies and even our nervous system with mechanical devices - what makes us the same person? AND, are we the same person if we can simply copy ourselves to a new body?
So last point - and it's not even my own. One of my colleagues brought this to the table today (literally at the lunch table) :P We were talking about the advancements and the potential/reality of human augmentation. Then he says something that makes complete sense to me. He said that we are at the point where our brain is evolving at a rate faster than our human bodies are. Just give yourself a minute to contemplate and wrap your head around the potential of that statement. To a degree - we have already done this (just not internally). Why else would we fly in a plane or drive a car? Well, I for one sure can't fly or run at 70+mph.
1. I apologize for the length.
2. I'm curious of your thoughts -- if you have another aspect of this, please do post.
3. Remember there is no "correct" answer, this is just philosophy.
4. There will always be more question than answers on this subject (at least I think so).
HAL-5 (mountain climb): http://www.engadget.com/2006/08/08/hal-robot-suit-almost-summits-with-quadriplegic-man-in-tow/