I have another question that I have no idea what the answer is. My question is, are humans the only form of sentient life on this planet?
To think about it, being self-aware is the decisive factor in sentience. But isn't the average pet(or any animal for that matter) with a brain bigger than an apple self-aware? I believe that this can be argued both ways.
You could say that animals are self-aware because they know when they are in pain or when they want to go outside to use the restroom. For instance, when my dog wants something--anything--he comes to me. It is then my job to figure out what he wants. I usually ask him something like, "outside?" and he responds to how much he wants what I said by how furiously he wags his tail.
Now, to be able to interpret cognitive speech into what my pet dog wants is an amazing feat. I don't know for sure how many different forms of life are on this planet, but I am sure that a very small percentage of them can interpret cognitive speech at the level that the average pet does(it has to be an animal with a brain larger than a walnut...my cat can only interpret clicking sounds as time to eat).
But you could also argue the other way and say that the same motivations that drive your pet are basically the same motivations that drive you. You eat when you are hungry, you go to the restroom when you feel the need, and you sleep when you feel tired. The majority of the things that have a basic hold on your life are the same driving factors in all life.
The major difference I see between humanity and the other forms of life that are less sentient(I guess that would be the right term) is that we have speech. When humankind developed speech, most of the other forms of language became obsolete(that doesn't mean that the other forms of language didn't work).
Speech is obviously a better form of communication than what dogs have, but it doesn't mean that we are the only beings that communicate.
Could it be possible that without speech sentient life couldn't exist?
Just a few thoughts.