On my English wwwboard, we had a random little discussion about the age-old question, "If a tree falls in a forest, and nobody's around to hear it, does it still make a noise." I thought that the direction the conversation went showed how you can approach an argument from a presuppositionalist point of view (not that I did an especially good job at it, but the idea is there).
Karyn: Question...if a tree falls in the forest and nobody is there to hear it does it make a sound? I think it depends on what you think sound means, does the tree make the air vibrate aboud it becasue it fell...yes. But is there anyone there with ears that can convert the soundwaves into hearable sound...no. So what's the answer? I don't know, and thoughts on my random question!
Madison: Yes, the tree makes a sound when it falls. Even if no one hears it, it still makes a sound because every other time that a tree falls in a forest it does make a sound, and so why should it be different whether or not there's someone there to hear the noise?
Karyn: True, the sound waves are still there, but is sound the waves themselves or our ears interpretation of them?
Sam: Can you prove that the soundwaves are still there? Can you be absolutely sure of something you cannot observe? Or is the most you can say that since every other time a tree has fallen it has made noise, it must have made noise that time? You are using inductive logic to make that assumption, which can only ever be probably true, never absolutely true. All of science is inductive, so none of it is absolute.
I'm giving the ideas of David Hume here, the great skeptic. Question everything, he said. However, since my worldview is not founded on science, but on the absolute Word of God, and that Word says that God has set certain laws in place to govern nature, I can be absolutely certain that the tree made a sound when it fell.
This is something I've been learning this year: everything comes down to worldview and basic presuppositions. Even a question as "simple" as that.
Karyn: nice answer Sam. Personally, I think that sound is only present in the mind, that is, moving airwaves are not "sound" until they enter your ears and then your mind iterprets them. So I would say no, the tree did not make a sound. But I see your point, and agree with it. Again, it all comes back to what you see as "sound".
Sam: Here's an example from David Hume: you hold a marble in the air and let go. What happens? It drops to the ground. Why does it drop to the ground? We want to say its because of gravity. Gravity pulls it towards the ground. But what is this gravity? How can you prove it exists? Well, we've done lots of tests on it and we know that when you let go of anything and it's not being supported, it will drop to the ground. That's the force we call gravity.
Here's where Hume throws in the twist: How do you know that gravity exists at all? Why couldn't it be that when you let go of the ball, the ball just happens to decide to fall at that very moment, and our experience is merely a series of coincidences that support our construction of gravity? This seems highly unlikely, but we can't discredit the idea entirely because we cannot prove that everytime anybody anywhere falls to the ground it's the result of gravity. Gravity could be nonexistent for all we know.
By extrapolation, you can never prove that causes and effects exist in general. It could very well be that we have the most remarkable set of coincidences taking place time and again, but one thing never certainly caused another to happen. That's the very heart of skepticism: how can you know anything?
Therefore, it goes even deeper than defining sound. You can't even prove that the tree obeyed any laws of nature as it fell. It didn't have to produce sound waves, because there is a possibility that sound waves exist independently and are not caused by anything. So even the question of whether or not the air vibrated when the tree fell is up for grabs with this question.
Madison: Okay. So why can't I jump off a cliff and fly? If there's the possibility that gravity doesn't exist and it's my choice, why can't I fly? And marbles have intelligence? Because if it decides to fall, then it must have a brain of sorts. If everything is coincidence and choice, then everything must be able to think.
And does China exist?
And if a tree falls in the forest and there's no one there to hear, does it really matter if it makes a sound?
Anyway. Some things we accept as true, whether or not we have actual proof. If a person is present when a tree falls, the person hears a noise. The chance the the tree would not make a sound falling, whether or not the sound is heard, is very, very small. The tree falling will cause vibrations, or sound waves. That the fact would change because someone is not there is improbable.
Claire: To add my two cents...
"If everything is coincidence and choice, then everything must be able to think." Nope, that doesn't logically follow.
You do understand the difference between inductive and deductive reasoning, right, Madison? All science can give is probability. Something completely different than what we hypothesize might be going on.
Does China exist? I believe so, but I don't know so. That's an important distinction. I believe in God's existence more firmly than I believe in China's existence. When you boil it down, the argument to convince me China does exist would run something like "well, lots of people say it does."
"And if a tree falls in the forest and there's no one there to hear, does it really matter if it makes a sound?" Maybe not. How many angels can dance on the head of a pin? :) The larger point here is that you're willing to take scientific probability as the only convincing way to "prove" something. In other disciplines, you can prove something logically, but in science, you can get only a probability. Scientists have been proven wrong time and time again throughout history. They constantly revise their ideas - the definition of scientific fact is basically one that the general scientific community supports. Science doesn't claim infallibility. In fact, it's the worst discipline in which to seek truth.
Madison: Going by Sam's example of Hume's work. If the marble decides to drop, then logically it has to have some sort of brain. Something can't decide to do something without being able to think. If the marble does decide to drop, then something inside that marble is telling that marble to drop, if it's not gravity forcing that marble to drop.
Okay. So if everything is coincidence, then not everything has to be able to think. But if everything is choice, then everything must be able to think to some extent. If everything is coincidence and choice, then many objects must be able to think to some extent.
Inductive is inference; deductive is...where's my geometry book when I need it. But yes, I know the difference.
Really, nothing is the best discipline in which to seek truth. Honestly, nothing really can be proven to be certain. cogito ergo sum. The only thing Descartes knew for certain was the he was real. But you can't even know that for certain. How do I know that I'm real? I don't. So how do I know anything is real? I can assume, but that doesn't make it true.
That's what scientists do. They carefully observe and determine what is most likely to be true at the moment. And if they're not certain, they'll keep searching. Otherwise, there wouldn't be scientists. Scientists search for ways to explain this world and why it works the way it does.
What can you prove logically? Very little. Just geometry proffs. :-)
I'm open to logical arguments, but the fact is that you cannot logically prove philosophical questions. Philosophic beliefs are what many thinkers thought were logical, but maybe really aren't.
If a tree falls in a forest and there's someone there to hear, the tree makes a sound. How likely is it be different? The tree falling will cause vibrations which will carry sound. And something will be there to hear. Like other trees, and maybe a squirrel or a fox. Maybe not a human, but other things can receive sound too.
Basically, it's a matter of what you're willing to believe. I'm willing to believe that the scientists tell me, if it also makes sense to me. But I'm not willing to believe my chemistry book because it tells me that there's no way to really prove that atoms exist, which is utterly ridiculous because in my geometry book, there's a picture of gold atoms taken by Japanese scientists in 1979. :-)
Sam: You're actually proving my point with what you're saying, Madison. Here's why: my basic point is that you cannot know with certainty that the tree makes noise when it falls. You can only know that it most likely makes noise. You can never prove it absolutely, as you've admitted. But my point is that, by extension, how can you truly be certain of anything? You say "I'm willing to just trust the scientists." Scientists have been proving themselves wrong since time began (just think of Aristotle, who single-handedly set scientific process back 1000 years with his wrong-headed theories). You really can't be certain that there are causes and effects to anything because of the possibility that there are just a mass number of coincidences taking place in our perception.
Here I'd like to clarify something: using "decide" to describe the ball's actions was unhelpful. I did not mean that it actually made a conscious decision to fall, but rather that it just happened to fall to the ground at that exact moment.
You summed up what I'm trying to say here: "How do I know that I'm real? I don't. So how do I know anything is real? I can assume, but that doesn't make it true." That's exactly what I'm trying to tell you. You don't know anything for sure, but the reason you don't is because of your basic assumptions about how life works. Are you truly willing to base your very notions about reality on the work of scientists who have been proven wrong time and again? People you can never be sure are right?
That's the benefit of Chrisitianity: because of my basic assumptions about reality, I have complete confidence that when a tree falls, it makes a sound, because I believe that God created the laws of nature and the laws of cause and effect. Do you see how that works? Your basic assumptions about the world only lead you into uncertainty about the nature of reality, while mine allow me to be certain about that nature.
Sadly, it was at that point that Madison, with whom we've had many arguments of this vein before, decided that she didn't want to have another religious argument and withdrew. And to be honest, I don't totally blame her. Hopefully, though, this has planted a seed that may someday bear fruit. I can only pray.