Originally posted by Hurkyl
The great thing about human thought is that we can think about what we can think. Recursive logical structures are exceedingly powerful...
At "first order", you may be right and we cannot conceptualize infinity at all.
However, at "second order" we can talk about first order thought itself. We can talk about things that fail to be conceptualized at the first order level and analyze how and why we can't conceptulaize it at that level, allowing us to synthesize second order concepts.
In particular, I can think about infinity without having to simultaneously think about everything "in" that infinity.
That addresses your argumentation, but I think you're thinking about infinity in entirely the wrong way. Most of these arguments that we cannot conceptualize infinity, et cetera, et cetera, are highly dogmatic; if you refuse to step boldly forward and try to figure out what you mean by "infinity", then, by golly, you will not be able to talk logically about it!
On the other hand, mathematicians do step boldly forward. We distill the "essential elements" out of peoples' vague ideas about infinity until we get a nice, precise definition appropriate to the context, and we get a lot of useful mathematics out of it.