I think your suspicions that there's a confusion in the use of the word "nothing" is on the right track. You can get yourself into a bind -- and people have for millenia -- if you assume that every word, in order to be meaningful, must refer to something. Because then in order for the claim "There is nothing in that drawer" to make sense, it seems there really has to be something in the drawer. And now "nothing" seems as if it's referring to something after all -- maybe "emptiness", or "space", or what-have-you. For some more on this, see Question 49 .

Sometimes, philosophers use the term "theoretical" to apply to certain statements in a scientific theory. Sometimes, they use the term to apply to certain entities whose existence is postulated by a theory, viz., those entities that are not directly observable. In the latter sense, they are contrasted not so much to "non-empirical" entities, but to observable ones. There is a lot of dispute about what "not directly observable" means. Are entities that we can see only with a telescope "directly observable"? Only with a microscope? Only with my glasses on? This kind of continuum has led some philosophers to declare that all entities are in principle observable. And others to hold that no entities are directly observable except "sense data", categorically unmediated sensory experiences. If you do think there are theoretical entities, or that most mature sciences contain statements with terms purporting to refer to them, then a major issue in the philosophy of science is what to make of (how...

You might not want to withhold the term "real" from all entities that don't exist in the physical world. For instance, you might want to say that the number 17 is real or that the thought that 17 is prime is real -- though you might be reluctant to say that that number or that thought exists in the same way that the Empire State Building does. But then, you ask, what about the natural number that is between 17 and 18? Might we say that it too is real, except not in the sense that 17 is? No. That would be to court confusion. To say that something isn't real or doesn't exist, isn't to say that it really does exist though in some especially attenuated way. See also Question 49.

Can it be talked about? Well, we do , so it can. If we could talk only of that for which we possessed definitions, there'd be precious little talking. But you raise a puzzling question: What must we know about an object in order to talk about it? You might think you'd need to know some characterizing property of that object, i.e., some property that only that object possessed. But is that so? It seems I can talk about Pliny -- but I couldn't really give you some property that only he possessed. I barely know anything about Pliny and the little that I do know doesn't distinguish him from many people. So, how can I talk about him? These questions are at the center of Saul Kripke's famous lectures, Naming and Necessity . You might also find this article in the Stanford Encyclopedia of Philosophy to be of interest.

I'm not sure why you think there's a general answer to your question any more than there is to the question of why people become doctors, or gardeners, or urban planners. Some people go into philosophy because they love reading and writing philosophy, some because they love to teach it, some because it's just the thing they've been doing since they were 17, some have no idea why they're doing it. And why aren't philosophers "thinking up the answers to the world's problems"? Well, one response is: they are. The problems of philosophy are as much a part of the world as any other. In fact, they've been part of the world for far longer than most problems. Perhaps by "world's problems" you mean something like "practical, pressing problems involving human suffering" -- that's often what people have in mind when they use expressions like "real" problems, or problems "out in the world". Again, I don't know why you expect a general answer to that question any more than there is one to the question...

I'm not sure how one could be "100% sure". Perhaps (perhaps!) thereare some claims about the natural world of which one could beabsolutely certain, like the fact that I was born to parents and nothatched from an egg, but I don't think most claims about the future areones we can be so certain of, certainly not a claim like "My wife willnever discover that I cheated on her." But if you want to takea case where we can be confident that the person cheated on will neverdiscover, let's imagine that your wife has asked you to promise herthat you will never have sexual relations with another person evenafter she, your wife, has passed away. Now she passes away. Surely wecan be "100% sure" in this case that she will never be hurt by your"cheating" on her. (I'm obviously assuming here that she won't bepained in some afterlife.) Would it be immoral to? I know somepeople who say it wouldn't be; that thinking so is a habit-inducedillusion. I also know people who would insist that it would be wrong;that...

If your life now has no meaning, no value or point to it, then having alot more of such a life isn't going to improve the situation. A wholelot of nothing doesn't amount to much.

Neither archeology nor any other science "proves" the existence of anyobject — if by proof one means considerations that are incompatiblewith the object's non-existence. At best, science will give one goodgrounds for believing in God's existence. Should that happen, I suppose there mightstill be work for faith to do: it could be needed to take you from goodgrounds to absolute conviction.

First, I'm not sure I'd say that my brain makes my decisions for me. I make my own decisions. When you win a game of chess, it's you who won it, not your hand (which you used to move the pieces around). But alright, so I use this tool, my brain, to make my decisions and, yes, I didn't ask for this particular tool and, yes, it's functioning might follow rules that I didn't have a say in constructing. Some people do think that this poses a big challenge to our possession of free will. And if having free will is necessary for being responsible for our actions, then some people think this poses a great challenge to our taking responsibility for our actions. Others, however, believe that there is no incompatibility between all these facts about how my decisions get made and my having free will. You might look here (and further references in it) for an article from the Stanford Encyclopedia of Philosophy.

It is interesting that many people, when they think of thosecircumstances that almost compel an adoption of a religious outlook,think of the death bed. They rarely think of how the world of theliving might strike one (and I'm not thinking here about arguments from design). But to turn to your question of whether anyone can ever look death in the face and remain an atheist, David (" le bon David ")Hume is a fine example. He used to drive James Boswell mad in hisrefusal to embrace the Christian faith: "Read Hume till you was sick,"one of Boswell's journal entries reads. Boswell even had dreams of Humeconfiding in him that he really was a believer. But it was all a dream.When Hume was dying, he used to entertain a veritable procession ofclerics eager to witness his conversion. But they all left himdisappointed. When Boswell told Samuel Johnson of this, the latterframed a most ingenious explanation ( The Life of Johnson , 16 September 1777): Boswell : Isaid, I had reason to believe...