6. How do you define what truth is?This is a bit of a non-sequitur, but let's humor the idea. Things that are true are, in general, dealing with matters of factual significance. For example, it is common knowledge that grass is generally green. This is true regardless of belief. Beliefs are not necessarily true, in this way. A simple example of contrast is that some people believe that coffee stunts growth. Regardless of how one feels about coffee, there is no evidence to suggest this as factual. This is therefore not a truth. Similarly, such effects (the greenness of grass or the average height of coffee drinkers) can be observed and quantified. In this sense, truth is a very real thing.
This definition is inclusive of things only which can be tested and verified. If the average color of grass were to become red, the truth of the green grass statement would no longer hold. If a god is true, therefore, it must be verifiable. Simply holding a belief that something is true doesn't make it so, even if the entirety of humanity believes it. Faeries do not push flowers out of the ground, and storks do not deliver babies, regardless of how true someone might believe those statements to be.
7. Why do you believe your atheism is a justifiable position to hold?This is the first intellectually dishonest question on the list. The preceding questions could have been written off as misunderstandings, but this question demonstrates the full dishonesty apparent in this string. This begs the question that any belief which isn't in accordance with the author's own is somehow unjustifiable. It further begs the question that all beliefs must be justified, which directly incriminates its author to do the same.
However, I shall ignore even this grievous level of ignorance, and try to rephrase the question thus:
What makes a belief justifiable?
Beliefs are justifiable when they fall in accordance with evidence. Here, too, the question is still imperfect, because it's conflating the two definitions of belief. On the average, these definitions are as follows:
1: To accept something regardless of its merits.
2: To accept something based on previous experience and observation.
The first kind of belief is the kind of belief that makes one believe that the world will end tomorrow, regardless of the fact that it hasn't happened before, and regardless of the fact that everyone to predict it so far has been wrong.
The second kind of belief regards things one does because it has worked before. Turning the key in the car to start the car, for example. If a person did not have prior experience of this working, one would likely not rely on it to work. The fact that it has worked almost flawlessly in the past causes you to believe that, when you wake up tomorrow, your car will start when you turn the key.
In this way, a belief can be said to be justifiable if it is founded in a reasonable truth. One generally tries walking across a room, rather than pushing off a wall to cross that room, because generally gravity works. This is a justifiable belief, that taking a step will in fact propel you. Residents of space vehicles will indeed tell you that, in exceptional circumstances, walking is ineffectual. In this case, it would be an unjustifiable belief.
So to the original question, do I think that not believing in any god is a justifiable position, I would have to say yes. I tend not to believe in things which are not evident, like flying saucers. I would offer as a rebuttal, does the author of the list think that his lack of belief in alien abductions (leprechauns, satan, bigfoot, unicorns, brownie monsters...) is justifiable? Is it justifiable for the same reasons as my atheism? Similarly, is his own belief in a god less justifiable simply because people believe in other gods? Is his lack of belief in Mohammed as a prophet justifiable? So on and so on.
8: Are you a materialist or physicalist or what?Apart from being a terribly worded question, this also demonstrates the author's inability to understand that these are not religious views. Many Christians are most definitely materialists or physicalists because they believe that god is literally a real being. Although he is claimed to exist outside of time (whatever that might mean), the soul and spirit are most definitely real things to them.
However, this is a veiled tu quoque on my part, so let's sort it out. Both definitions on his website are incorrect. A materialist, much like a physicalist (in fact the terms are quite interchangeable more often than not) believes that things within our own universe are comprised solely of things that can exist within our universe. This is based largely on the fact that most things one interacts with are indeed physical. More recent scientific evidence supports this claim. This claim does not speak to any facets of religiousity or theism and therefore are outside the purvey of atheism. This includes other philosophies like nihilism, humanism, secularism, and so forth. None of these is religious, let alone theistic, and therefore are separate issues to be addressed. Some atheists are deist, even. It's not a dichotomy.
I don't personally hold a belief on what exists outside the confines of our timespace. Whatever may be there, it can not ever interact with us here, regardless of whether it is or is not material. If a god is claimed to be there, then such a god can have no bearing on what happens within our own universe and timeline. Such a thing would certainly not be a god. Any number of infinite beings can exist outside of our timespace. Any thing that can affect things within our timespace, however, must ultimately reside here. Anything that happened before the big bang could not affect what happened after. Similarly, 'before' the big bang is the same as 'outside the universe.' Before and after lose meaning outside of our dimension as we currently understand them. Other places will have their own timelines. There might literally be an infinite void, or an infinite number of them, between our timespace and the adjacent one. These things are irrelevant to atheism.
9: Do you affirm or deny that atheism is a world view? Why or why not?Well, that's technically two questions, but I can see why he threw them together. Also, he's not exactly got a good set of questions for what defines a world view (because it begs too many questions, for one). A world view is basically the philosophy by which people tend to live their lives, or at least explain some of the phenomena therein. Worldviews do not necessarily include topics such as purpose, or why suffering exists, or if morals exist. These are a few of the preconceptions that have been thrown in by the author of the list, not ones that are necessary to form a worldview.
In the sense that atheism only deals with belief in a god (and not knowledge, but I'm certain we'll come back to that, so I'll leave it here for now), I suppose it's possible to say that every world view is atheist to some degree. Again, this is where definition two of the atheism comes into play. At no point is he asking if other religions are worldviews. This is a subtle duality, whereby if atheism isn't a worldview, then fundamentally religions are not either. This question is no different from asking if Islam or Judaism are worldviews.
With that logical conundrum aside, I think I understand the purpose of the question. It seems that the question should have been phrased as follows:
Can you explain natural processes without a god?
Yes. I can understand how thunder works without Thor. I can understand how lightning works without Zeus. I can understand how rainbows are made of light and water molecules, and that the first one wasn't made by god after a flood. I can use these observations to fuel my understanding of the natural world. In this way alone, atheism can be a world view, in that it doesn't use god to explain things I don't understand. In any other sense, no, atheism isn't a world view.
10: Not all atheists are antagonistic to Christianity, but for those of you who are, why this antagonism?Again, this is a conflation on the author's part, I think. However, I'm going to address this question as it stands this time, because it's not my job to make sure he's got his things right.
I'm not being antagonistic, is what you need to understand. I'm showing you some of the very real concerns I have with the religion you are supposedly promoting. If I'm using your belief as an example of something, that doesn't mean I'm attacking you. I'm showing you legitimately why I don't believe what you do. If you're going to take every single criticism as a personal antagonism, then you're not understanding my responses. It's not my job to explain your religion to you; it's your job to defend your religion to those who don't agree with it.
Let me phrase this another way:
Not all Christians are antagonistic to people who don't agree with them, but for those of you who are Westboro Baptists, Spanish Inquisitors, witch hunters and so on, why are you?
We aren't asking you to explain why some Christians burned witches, led inquisitions, or are the main reason the Lords Resistance Army is in operation. You know that this is an intellectually dishonest question. If we're antagonizing you at all, it's because organizations that are working in the name of your religion are attempting to limit basic human rights. It's not antagonism to have an opinion different from yours. It is, however, antagonism to protest military funerals, deny LGBT individuals marriage certificates, or to burn 'witches' who you simply disagree with. It's your religion, therefore it's your onus to explain it.