The Nature of Consciousness

In The Singularity is Near, Ray Kurzweil explores the age old question of the nature of consciousness. He explores the significance of this idea in light of the tremendous technological capabilities that humanity will soon acquire.

Since the dawn of culture, humans have speculated on why we have subjective experience through the mind and body that we call 'self'. Why is it that we are who we are? Our inability to truly grasps these concepts on a scientific level have lead to beliefs such as the existence of immaterial souls. However these types of beliefs have no supporting evidence and no basis in reality.

In his book, Kurzweil performs several thought experiments to try to make the concept clearer. In the first, a biological human brain is slowly replaced with nonbiological hardware. It is logical to reason that after the brain is completely replaced by the nonbiological substrate, the subjective experiences of the individual will remain the same. If it were my brain, I would still be me, and I would still think and experience the world as I always have. This is not a giant leap of assumption, as the atoms molecules of our brains and bodies are continually changing anyway. Every month the atoms constituting my brain will become completely different, the only thing that remains somewhat constant is the pattern of matter and energy that defines who I am.

Now lets take the idea further and explore what happens if that same biological mind were scanned, copied, and then instantiated on a completely new substrate. This is where the concept becomes blurry and does not lead to an easy explanation. For one, the copy of the mind would think and act exactly like the original. It would claim to have had the same experiences as the original and would be objectively indistinguishable from the original. However, if it was my mind that was copied, I would still be experiencing life subjectively through my biological brain. Clearly I could not be both me and my copy at the same time. If this process was for the purpose of transferring my mind to a non-biological substrate, I would most likely object to the destruction of my biological brain after its completion. Although the pattern of my mind has been transferred, my subjective experience has not. Clearly there must be something else besides my pattern of matter and energy that represents the true me.

But what confuses the matter even further is the fact that the first process of slowly replacing my mind is actually no different from the process of copying my mind and destroying the original. And so there lies the dilemma. At what point does subjective experience begin and end.

This question will have immense importance in our near future as technologies such as brain augmentation and mind uploading become possible. I believe, however, that our increased intelligence and technological capabilities over the next 20 years will finally reveal the answers to these age old questions.