First, some definitions to make sure we're all talking the same language.
Gnostic: The opposite of agnostic, a gnostic is one who believes that the answer to a particular question is knowable. The particular question is most often "does god exist." In the most commonly used sense, a gnostic believes that the question "does god exist" can be answered.
When I claim to be gnostic, I don't always mean we can prove 100% one way or the other. Rather, we can demonstrate that one answer is far more probable than the other. Remember that just because 99% < 100% does not mean that 99% = 50%. This is a common fallacy for the "but we can never really know" crowd. Also, my gnostic use of "knowable" typically means "knowable through science or philosophy," which is based on a philosophical definition of knowledge (see below). As I've already explained, faith doesn't actually lead to knowledge.
Knowledge: Knowledge is a single or set of known facts. Philosophically, a known fact must fit at least three characteristics:
1. A known fact must be believed. We don't know something we don't believe.
2. A known fact must be true. If the term knowledge is to have any significance beyond mere belief, then it ought to be impossible to know something that isn't true.
3. Belief in a known fact must be justified to the exclusion of falsehoods. Knowledge is not coincidental. If I believe in something without reason, and that something just happens to be true, I haven't really obtained knowledge. To have knowledge, I must be able to demonstrate that my belief is true to the exclusion the other possibilities. If I know that 2 is even then I should be able to demonstrate that it is even, and I should also be able to demonstrate that it is not odd.
The Scientific Method: The method science uses when faced with any question.
Natural: Things that can be dealt with using the scientific method.
Supernatural: Things that cannot be dealt with using the scientific method.
God: A conscious, supernatural being that has at least some extraordinary capability to influence the natural world, and probably created said world.
Now on to the essay
What is a Scientific Question? What is the Supernatural?
In Other Words: Why I am a Gnostic
Many people have made claims of agnosticism. Claims like "we can never really know," while not strictly agnostic, are almost always used in an agnostic sense. "We can never really know, so we have to use faith," or "we can never really know, so there is no truth," or even jumping from "we can never really know," to "we have no idea what the odds are." This is especially true with regards to gods. The vast majority of theists are agnostic; they claim that the existence of gods is not a scientific (or philosophical. They mean this, but often don't state it) question and thus must be decided by faith. They will often defend their belief with "well you can't disprove it."
I claimed agnosticism some time ago, but I wasn't really agnostic for very long. I, like many atheists out there, attempted to use agnosticism as a sort of middle ground between theism and atheism (it is not. This is a fallacy). But I've always applied philosophy and often science to questions of theology, so in that sense I've always been a gnostic. I never really believed the question was unknowable (at least while I believed it to be meaningful. There was a brief period of "it's unknowable and therefore meaningless," which has since been the conclusion I've always drawn from complete unknowable-ness), just that I hadn't quite figured it out yet. I've always believed that religious claims were scientific and philosophical claims. To understand why, you'll need to understand the scientific method.
1. Ask a question or identify the problem. Figure out what question you want to answer
2. Do some research. Find out what others have done before you. Learn answers to similar questions and try to apply them here. Use some philosophy to gain insight.
3. Make an educated guess, which we call a hypothesis. Using your research, determine what you think the answer is. THIS DOES NOT REQUIRE FAITH. You've already done the research, so you already have at least some evidence. You've thought about it philosophically, so you already have some reasoning. Also, this is just a guess, and will be disbelieved if the evidence turns against it. Don't get too attached to your hypothesis.
4. Devise an experiment. If your hypothesis is correct, what happens? Figure out a situation where your hypothesis leads to a prediction.
5. Test your hypothesis by bringing about that situation. In other words, perform the experiment.
6. Observe the results and see if they matched your prediction. If they did not, return to step 2. If they did, proceed to step 7
7. Share your results so that others may verify them independently. If others obtain different results, return to step 2. Otherwise proceed to step 8
8. In conjunction with others, repeat steps 4 through 7 to continue testing your hypothesis. After many successful tests, proceed to step 9
9. Combine your hypothesis with other successful hypotheses to create a theory. THIS IS NOT JUST A GUESS. A scientific theory is not "just a theory." It is a group of hypotheses that have passed extensive testing to become more than just a guess. Theory meas something very different in science than in the vernacular.
10. Repeat indefinitely
Odd as it sounds, step 10 is important. Science constantly needs to use its theories to make more predictions so it can perform more experiments and provide stronger evidence. Science suffers from being unable to affirm its theories with 100% certainty. However, repeated successful experiments provide ever increasing certainty, asymptotically approaching 100%. Because of this, science is never really finished. While science may never give us 100% certainty, it gives us enough certainty to use its theories to develop technology. With enough certainty, we can claim to have achieved knowledge. We believe the theory, and the theory is justified by the evidence. When the theory is true, we have knowledge. When it is not, we do not have knowledge. We may never know when our theory is actually knowledge, but we do know that our theory is probably true, and thus we probably have knowledge of the type philosophers like to talk about.
Step 7 is very important because it ensures objectivity. This is how science refutes claims such as postmodernism. Some people may say "sure, it's true for you, but if you look at it a different way..." Science relies on reproducibility, its why lab notes are supposed to be so detailed. Once you perform an experiment, you should explain your methods with enough detail that others with different biases can perform the same experiment. When people of widely differing genders, cultures, and viewpoints all obtain the same results, then science claims the results to be objective. Thus, science can make truth claims that apply no matter who you are, where you're from, or what your particular prejudices might be.
Also, I should point out that "science gets things wrong all the time" can be a little misleading. For instance, everyone knows that Einstein showed physicists they'd been "wrong" for centuries. But what isn't so well known is that most of these cases are more "science gets things almost right all the time." Newtonian mechanics works very well until you hit speeds that are significant percentages of lightspeed or find yourself in a very large gravity well. What Einstein really showed was that physicists had been approximating for centuries, and that their approximation were very accurate until the speeds involved got way too high, at which point a more accurate approximation was necessary. After all, physics is Backwards Compatible.
So remember that wrong doesn't always mean hopelessly inaccurate and unreliable. While science is frequently "wrong," it is often just "slightly wrong," and almost always getting "less wrong." As Isaac Asimov puts it.
"When people thought the earth was flat, they were wrong. When people thought the earth was spherical, they were wrong. But if you think that thinking the earth is spherical is just as wrong as thinking the earth is flat, then your view is wronger than both of them put together.”
Source (A great read. He explains this concept far better than I can.)
Now, what is a scientific question? A scientific question is any question that can be examined using the scientific method. Basically, if we can devise an experiment for which one answer predicts different observations than the others, we can use the scientific method to answer the question.
For instance if I claimed that there was a supermassive black hole floating halfway between here and Pluto, the truth of my claim would be a scientific question. Such a black hole would produce easily observable effects, and by observing that no such effects occur we can conclude that there is no supermassive black hole floating halfway between here and Pluto.
It is important to note that the object in question need not be observed directly. We just need to have some observable effect that differs for different answers. The fact that observing atoms directly was impractical at the time did not prevent physicists from developing atomic theory and using it to win WWII. Scientists could observe the effects of atoms. They were able to determine that if matter were built from atoms, certain things would behave differently than if matter were not built from atoms. Atoms didn't need to be observable to be scientific, they just needed to make an observable difference in the universe.
To say "it's not a question of science," is to claim that the scientific method cannot be applied to the question at hand. In principle, the scientific method can be applied to any question for which answer A predicts a different observable effect than answer B. If a question makes an observable difference in the universe, then that question is a scientific question. Non-scientific questions make no observable difference in the universe, and if there's no observable difference, then does the question really matter?
So what about the supernatural? The supernatural, by definition, is outside the purview of science. Yet many people claim that supernatural entities (including but not limited to gods) cause observable natural effects. If this is true, then these "supernatural" entities are not supernatural at all. Causing observable natural effects places these entities within the purview of science, and thus makes them natural. Since anything that causes an observable effect can be analyzed by science, anything that causes observable effects is natural, and thus only natural things can cause observable effects. If it is to meaningfully impact our lives, the paranormal must actually be normal; the supernatural actually natural. If something is indeed supernatural, then it is ultimately meaningless because it can make no observable difference.
So what about God? God as defined above cannot possibly exist in any meaningful sense. If God is to remain beyond scientific scrutiny, then he cannot impact the natural world and is thus ultimately meaningless. Any meaningful god must be natural, and thus any meaningful god can be examined by science. Religions claim to be very meaningful, often claiming to be the most meaningful thing there is or ever will be. This claim is scientific. Most religions claim that the universe with God is different from the universe without God. So let's test that difference. Let's look for evidence. Let's perform an experiment. Let's have others replicate our results to ensure that they are objective. If God really means so much, then let's put him to the test. Let's stop using faith and start deciding this question in a defensible manner; in a manner that allows us to argue not only that we are right, but why we are right, and why the opposition is wrong. Let's stop saying "I believe this" and start saying "this is true because..."
Let's gain some knowledge.