I have read that the human genome (and some others) are replete (or at least tainted) with snipets of viral genetic code that gets transmited (piggy back) during cell devision and are now incorperated onto our genome. Have you heard of this?
Yes, that is true. A lot of our DNA sequence doesn't actually encode anything active. There are long non-coding sequences. Our genes are interspersed with non-coding sequences called introns that have to be spliced out. Many of these introns are thought to be dead viral genomes.
There are many virus families that cause human disease that integrate their genetic material into our DNA. The most famous ones are the HIV virus (well, after changing it from RNA into DNA), the hepatitis B virus, and the herpes viruses (of which at least 8 routinely infect humans). In ALL of these cases the integrated DNA becomes a permanent part of the genetic material of the infected cell. So it's easy to imagine us being infected with viruses that infect our germline cells (the cells that produce sperm and eggs), and some of these viruses may not be viable -- so we permanently get that viral genome passed through our offspring. Of course it would have to be incorporated in a way that does not disrupt an essential gene.
If our genome contains traits that are no longer expressed like dormant genes for a tail, then this dormant tail is also part of what we are. So then if this biological definition of human is constantly changing as we regenerate what it is to be human must also be constantly changing as well. What is the point of departure when we become something else?
You can always divide, divide, and subdivide. But this is a big issue in biology these days -- not so much with big organisms (which are pretty easy to classify on taxonomic and genetic grounds), but rather with microorganisms. They're doing things like 16s subunit RNA sequencing (which is a highly
conserved part of the genome) to define species among microorganisms -- because it's just too imprecise to use morphologic categories like "gram positive" or "spirochete" anymore. At any rate, we evolve too slowly to have to worry about a shifting definition of us. Furthermore, I'd argue that the point of exclusion
among humans versus nonhumans is not all that difficult to find -- because the closest living nonhumans on the planet are chimps, and you might have noticed that they look a bit different
I think the chimp is acting more like a human in this case
Well yes, that's the point, and humans if they so desire can act like chimps. But the question isn't "what does it mean to act like a human".
I don't believe it is aware of what it is doing as a real human would be aware.
This response means that you're not responding to my hypothetical scenario, though. I posited a group of chimps that IS aware, that has complex language, technology, is able to philosophize and think abstractly and rationally, and can communicate using language.
For my scenario to be worth pondering (and worth a response), then you have to imagine the scenario in which such a thing is possible. Because I'd argue that the ONLY thing that causes people to claim that reason
is "what makes us human" is that these features happen not to be shared by other animals -- but if we suddenly discovered that they were
shared by others, then you'd suddenly have to find another way of defining us. So my argument is that humans have to be defined by the ONE THING that cannot possibly be imagined in other animals -- and that is how we are biologically defined.
As I've said before, many times, this conflict lies at the very root of all philosophy -- the fact that we can't stand being things
And I don't believe that the child with anencephaly fulfills all of the requirements of what it means to be fully human. And since she is biologically determined to be human her inability to behave in a mentally healthy manner points us toward a more complete definition of what it means to to human.
Are you saying that there are full humans and partial humans? Certainly this example is of a biologically defective human, but it's still without any possible argument a live offspring of our species. It's as human as anything else.
I wonder if it makes sense for me to say that the biological construction or biological makeup of a human being is only one (necessary) factor in the definition of what it means to be a human being? And since the biology of a human being is purely material I would further say that it is the 'material cause'.
I have to side with the existentialists here:
Existence comes first. Essence second. You have to define a human by the most universal feature, not by an idealized essence.
Your argument that I've quoted looks very much like Aristotle's metaphysical ideas, which I find to be not a very useful way of understanding things anymore. A human being IS a material thing. We can describe non-material things like abstract thought as unique elements of the human experience -- but unless it's universal among all
humans, sick or well, it cannot be said that this is what it means to be human.
I have thought about the possibility that we humans are in reality machines wholly explicable via material substance and forces. I wonder if your position entails this definition of man as mechanism? I don't think that is what you mean but I still must maintain that I find your definition of what it means to be human lacking.
Even if we were
entirely explained in biological terms, it wouldn't matter. It doesn't change the fact that we feel
and we experience
. The biological mechanisms are incidental to discussions like this -- I think we can take them for granted and still have a conversation about meaning. But if you're going to define humans based on an essential quality, you have to alternatively and adequately define all the members of our families and communities who lack that quality.