The Vagueness of 'Very'

Since nothing's been posted around here recently, I thought I'd post something in an attempt to stimulate conversation. The topic of the post is the vagueness, or lack thereof, of 'very'. Joshua, Andrew, and I discussed this on the way to Syracuse last week, so I'd especially like to get the opinions of others. But Joshua and Andrew are also encouraged to register their thoughts, of course.

It is clear that many predicates of the form 'very F' are vague. For instance, there seem to be borderline cases of being very tall, very nice, and so forth. What is at issue is whether the vagueness of expressions of this form is due at all to the vagueness of 'very' or whether in all such cases the vagueness is due to the adjective 'F' to which 'very' attaches. Or, in other words, the question is whether 'very' is vague at all.

One way to show that 'very' is vague is to discover an adjective 'F' such that 'F' is not vague but 'very F' is vague. Since the vagueness of 'very F' could not then be due to the vagueness of 'F', it must be due to the vagueness of 'very'. But are there any such adjectives?

On the way to Syracuse, Joshua, Andrew, and I puzzled over this for a bit. We each came up with different candidates for an adjective meeting the above condition, but many of the proposed candidates were either plainly vague or not clearly nonvague. However, one of us then suggested 'late'. This seemed like a plausible candidate. It seemed to us that 'late' is not vague but 'very late' is vague.

I would like to know what the rest of you think about this case. I would also like to know whether any of you can come up with a spatial adjective 'F' that seems not to be vague but is such that 'very F' is vague. (One might expect that if there is a temporal adjective, like 'late', that has this feature, then there is a spatial adjective that has it as well.) In addition, I would like to note that some (for instance, Peter Unger) have thought that adjectives like 'flat' are not vague, claiming that a necessary condition on something's being flat is that nothing could be flatter than it. But presumably 'very flat' is vague. Is 'flat' another plausible example that can be used to show that 'very' is vague? (I'm inclined to think not, since I think that Unger was mistaken. But I'm wondering what the rest of you think.)