For a similar issue, see Question 49 .

Yes, we do think that things exist which we cannot pick up or see. (For instance, we say that numbers exist, or that the center of mass of the solar system does.) What precisely do we mean by "exists" then? That's one problem you raise. I'm not sure how to answer it: the notion of "existence" seems so basic, it's hard to imagine much light being shed on it from other, yet clearer, notions. But you raise another question: whether there's something problematic in even asking what "exists" means. Your thought is that there is, since the question itself involves the notion of existence. I'm not sure that it does: In asking for clarification of a notion, we're not asking whether that notion exists (whatever that means). You might say that we're asking what "exists" means. And although it's not clear exactly what we're doing when we ask what a word means, it doesn't seem right to say that we're asking whether something exists. Of course, your paradox could perhaps be reinstated by shifting our...

If someone asks me what's in the refrigerator and I answer "Absolutely nothing", what am I saying? I'm not saying that there's something in the refrigerator after all, namely absolutely-nothing. What I'm doing is denying that there is something in the refrigerator. Although the sentences "The milk is in the refrigerator" and "Absolutely nothing is in the refrigerator" are grammatically comparable, their logical structures are different. In order for the first claim to be true, there must be something that "The milk" refers to and that something needs to be in the refrigerator. But that's not the case for the second claim. In order for the second to be true, the claim that there is at least one thing in the refrigerator needs to be false. It is not the case that in order for the second to be true "Absolutely nothing" must refer to something and that something is in the refrigerator. People have, for thousands of years, been misled by the superficial grammatical similarities of these two...

If everything that exists is finite and God is in some way infinite, then you're right that it follows that God does not exist. Does this prove that God does not exist? Well, the argument establishes this if its assumptions are true. The problem is that most people who believe that God exists will not acknowledge that your first assumption ("Everything that exists is finite") is true. So, in order to convince them, you'll have to give an argument for that assumption. Now that assumption isn't the same claim as the conclusion of your argument ("God does not exist"), but it is close enough that debates about it might well recapitulate debates about the original issue, namely whether God exists. So in sum, the logical form of your argument is great, but it's doubtful that it moves us much closer to settling the central question you raise about God's existence.

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 .

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.

OK, so I'm now imagining the winning lottery ticket in my wallet. Let me check my wallet. [Pause.] Damn. Not even the slightestsemblance of a winner. In fact, not even a lottery ticket. We do speak of a thing's "existing inone's imagination". But this doesn't mean that the thing in questiondoes actually reside in some very wispy way in your mind. If anythingdoes exist in your mind, it's the thought of the thing's existing, orperhaps an image of the thing. But not the thing itself. We are very close to a Grand Philosophical Headache: trying to understand what makes that thought or that image about the thing it's about. This is especially puzzling when the thing it's about doesn't actually exist at all.

Just a quick comment on your remark about (2). If there are no necessary beings, then the set of necessary beings is empty. The empty set is a subset of every set. (Every element of the empty set is a member of any given set — since the empty set has no elements.) Hence, if there are no necessary beings, the set of necessary beings is indeed a subset of the set of impossible beings, just as it is a subset of any set. I'm not quite sure what an impossible being is, so I'm not quite sure what the set of impossible beings is. It sounds to me like it's another way of describing the empty set. But whatever the set of impossible beings is, we know that, if there are no necessary beings, then the set of necessary beings is a subset of it . I don't see any contradiction here.

Your first question misunderstands the meaning of "nothing": if I come from dust, then there's something I've come from (namely, dust). But if I come from nothing, then there's nothing I come from — not the something that nothing is! See Question 49 for more on this. (You might also look at the reference given in the responses to Question 40 .) The more difficult question you raise is how something could have come from nothing, as physicists tell us is the case.

There is no thing that is nothing. To say that nothing is in the room is not after all to say that something is in the room, namely nothing. That's a confusion: see Question 49 for some discussion. You're right to observe that when someone says "I'm doing nothing", they're always doing something. But the right lesson to draw from that is not that "nothing" is actually a thing or an activity, but rather that what someone intends to communicate by saying "I'm doing nothing" is that they're not doing anything that you'd care to know about. Likewise, when you're shipwrecked on an island and looking out to the horizon and your friend asks you what you see and you say "I see nothing", you shouldn't think that "nothing" really refers to the water, the sky, the puffins, etc. Rather, you're trying to get across that you see nothing that your friend would care to know about at that moment (like an approaching ship).