[I'm presently getting packed for my trip back home for the holidays, where I'll finally go watch Serenity with my friends and family (woo hoo!), and put some new strings onto my violin (double woo hoo!). I never could figure out who decided to put the classical music capital of the world in a city with such vicious humidity and temperature swings; not a stringed-instrument player, that's for sure.
At any rate…]
In the future, what will define humanity? What will make it unique?
Soon, we will have the power to design our own DNA to specifications. If humanity is defined by a particular genetic legacy, when do we stop being human and become something else?
Soon, we will share the world with computer AI that would be increasingly comparable to human intelligence, and which will eventually pass us in terms of brute-force computing power. If we define humanity as meeting certain standards of intelligence, would a computer program that meets those standards be called human?
Soon, we will see tighter and tighter integration of organic and robotic components, entering into the realm of true cybernetics. People will enhance themselves with mechanical devices, perhaps replacing entire systems such as the skeleton with stronger or more efficient materials. Conversely, machines could be built around organic components. Can a human stop being a human and become a robot? Can robots ever become human? Are organic components even necessary to humanness?
Science has no answers, because science does not deal with such questions. These are questions of morality, of our understanding of humanity's place in the world. All the more reason to turn first to the Torah.
The commentators debate at length what made Adam the First different from all the creatures that preceeded him, some of whom were even manlike in form. Some say that Adam could create things; some say that Adam could name things, or communicate in general. The explanation that seems best to me, which I think was that of R' Samson Raphael Hirsch (or possibly derived from his teachings by someone else), was that Adam was the first physical being capable of prophecy. That is, Adam was a unique creation because he could transcend the physical world and reach up into the spiritual realms.
Without getting into complicated questions on the nature of the soul, I'll simply note that the experiences I have had (particularly with Tai Chi and the use of the Amidah prayer as meditation) force me to believe in a spiritual realm with which we interact. So I am willing to accept interaction with the spiritual as the definitive quality of humanness. I doubt machines could be spiritual beings; but more importantly, should a machine demonstrate transcendant spirituality, I would seriously consider whether it were not, in fact, human—or perhaps a distinct type of being on a similar level.
I am open to other suggestions, though the whole debate will remain academic for at least the next decade…