Sure. Even if existence is not a predicate, it's at least arguable that necessary existence is. (As Norman Malcolm pointed out years ago, there really are two versions of the argument, and the second one deals with necessary existence.) We doubt that existence is a predicate because, roughly, saying that something exists tells us nothing about what it's like. Not so for necessary existence. Not just anything could exist necessarily. The computer I'm typing on is the wrong sort of thing to be a candidate for necessarily existing thing. Assuming that some things are of the right sort to exist necessarily, necessary existence would be a predicate. Whether this is a defense of the argument all things considered is another matter. But I think the point made here is fair as far as it goes. A being that merely happened to exist wouldn't be a being than which none greater can be conceived.

I'd say it's an extraordinarily uncommon view among philosophers. Very few philosophers have believed it throughout the history of the discipline (Bishop Berkeley is the most obvious exception) and I can't think of any contemporary philosophers who do, though I'm sure there are some somewhere. Berkeley was an idealist (that's the usual name for such views) because he thought the conception of matter found in Locke, Newton and other thinkers of the time was incoherent. If you read his Three Dialogues Between Hylas and Philnous, you may find some of his arguments more interesting that you would have thought. We could add: orthodox theological views hold that not that our minds make matter, but that God creates the world. And accordng to that same orthodoxy, God isn't a material being. So the view that some mind may be the source of matter is actually not at all uncommon. And for various reasons, contemporary New Age and Magical thinkers often favor a view that puts mind first. If you want...

Of course, in a perfectly good sense of "exist", existence doesn't exist either. Existence isn't a thing, and so there is no such thing as existence, though of course, bears, bells and BMWs exist, to mention but a few. And yes: there is no such thing as non-existence, because "non-existence" isn't way of referring to a thing. But unicorns don't exist. Neither do square circles. And, according to some, neither do free lunches. No fallacy there. Does everything exist? Well, if "everything" means "all the things that exist," then everything exists. (Though of course, this doesn't mean that there is a special thing, namely everything , that exists.) But since, as noted, unicorns don't exist, it's not true that "everything" in the sense of "everything that might have existed" actually exists. It's likewise not true that that every description (e.g., "round square") picks out something that exists. The conclusion of the argument comes partly from trading on ambiguity. Related: ...

It seem that some issues are getting blurred here. You suggest that when we say there are no possible worlds with round squares, we're implicitly talking only about worlds where the concepts of 'round' and 'square' are as they are in our world, or -- perhaps you see this as the same thing -- only in worlds with beings who think the way we do. But that makes it sound as though it's a matter of how people talk or think. The real point is this: we use the words 'round' and 'square' to pick out certain concepts. People who don't speak English might use different words. Some creatures may not have these concepts at all. And there could be square things or round things -- things that fit the concept we're getting at -- even if there were no thinkers at all. But to revert to world-talk, there aren't any worlds where any round things are also square things --even though there might be worlds where beings use the words 'round' and 'square' to pick out concepts different from ours that don't exclude one another. ...

It's an interesting question, and to answer it, I'm inclined to turn things around. Let's start with what's clear: the fact that the rapist committed the rape seven years ago (supposing for the moment that this is the magic number) isn't a reason to let him off. In fact, the very way you pose the question makes the point. You ask about "the rapist" who committed "his crime" long ago. You've already take it for granted that we can say: this man is the one who committed the crime. And we can say it without worrying about how many cells have come and gone. So yes: there is something more -- or something other -- to the notion of a person than just the idea of a collection of cells. The something needn't be anything spooky. After all, a corporation can exist for a hundred years, even though all the people have changed and all the buildings and equipment it owns have gradually been replaced. Although saying exactly what sameness amounts to here is complicated, it won't call for talking about...

This is one of those cases where as long as we're clear on what we mean, there's not much of an issue. It would be perfectly in order to say "that creature existed two weeks ago; it was a chrysalis then." It's like saying that you existed lo so many years ago, though you were a toddler at that time. Leaving aside more radical doubts about identity over time, there's no problem with talking this way. If you say "that butterfly existed two weeks ago" and you mean something like "that creature, which is now a butterfly, existed two weeks ago" then there's nothing to worry about. But obviously if you mean "two weeks ago, this butterfly was around, as a butterfly," then you'd be saying something false. There are more subtler issues that a philosopher might raise, having to do, for instance, with whether the butterfly (or you, for that matter) is present at any one moment (as opposed to being a 4-dimensional being whose time-slices are present at various instants). But that question would come up even...

Sure. For one thing, nature doesn't care about our arbitrary units. Suppose we have a plank of wood that''s exactly a foot long. Now I define a new unit: a schfoot. Anything one foot long is exactly pi schfeet long. Is there any mystery about things being pi schfeet long? Also -- since we're setting aside issues about quanta and, I assume, the possibility that space is granular, can't we make sense of something changing length continuously? A twig that's a foot long and growing will pass through an uncountable number of irrational lengths on its way from being a foot long to being two feet long.

What fun! And indeed, it turns out that Giovanna picked my birthday to show me the error of my ways! :-) As it turns out, however, I don't think we actually disagree about anything. Giovanna has pointed out, in effect, that folks in her tradition use these terms to mark out a distinction (or, it seems to me, a set of related distinctions) that folks in my tradition would talk about in different language. Needless to say, that's not a comment on the value of either tradition nor on the importance of the problems. I'll confess that I don't think I have the differences here fully in view yet, but if I have it right, one distinction marked by the existence/being distinction is the difference between individual things that exist, change, have properties, etc., and the background against which the possibility of such existents makes sense. Existence, on this way of speaking, refers to the existent things, and being to this broader metaphysical background. Giovanna points to the problem of understanding...

No doubt there are philosophers who make a distinction of some sort here. (For any sentence of the form "There are philosophers who___" you have a good chance of saying something true...) But one is tempted to ask whether being is the quality or state of existing; not everyone sees a a distinction here. One possibility: not everything that exists is a being. (For example: water isn't a being.) So one might say that among existing things, being is possessed only by the beings . But now we want to know: what's a being? Is it, for example, an Aristotelian substance — something like a person or an animal? Or is it any physical object? (On that story, my thumb would count as a being, but Aristotle wouldn't agree.) Or is it any "mereological sum" so that not only me and my thumb would count as beings, but so would Charley, whose parts are Dan Quayle, the Empire State Building and the marker at the tip of Key West, Florida? (Mereology is the study of part-whole relations.) The question of what it is for...

I'd like to take this question in a slightly different direction. I accept the point made by Prof. George: we don't need to think of the phrase "absolutely nothing" as referring to something; the logic of "There's milk in the fridge" isn't the same as the logic of "There's absolutely nothing in the fridge." But I'd like to pick up on a point in my colleague Prof. Levinson's reply: that if there being absolutely nothing is a possible state of affairs, then reality contains that possibility. Start by mulling over the idea that there being absolutely nothing is a possible state of affairs. A person might wonder: is a state of affairs something? Are there such things as states of affairs? How about possible states of affairs? If so, then so long as there is at least one possible states of affairs, there's not absolutely nothing. Now suppose -- as at least some philosophers seem to -- that for it to be possible that X, there must be a possible state of affairs in which X is true. This brings us to a...