I'm not entirely sure that I understand what your argument is, but I think you're saying that different concepts represent the same ideas. I don't think concept

I'm not entirely sure that I understand what your argument is, but I think you're saying that different concepts represent the same ideas. I don't think concepts are distinct from ideas, so I'm not convinced by that. When the Greeks used the concept of democracy they were not accessing an ethereal plane outside of themselves. They just invented the concept and social practice in the context of their own historical reality. This is simply not the same concept as that used in the French Revolution, although there are important historical connections between the two. I don't know how you would go about arguing that, despite the fact that these are different concepts, they are somehow, unbeknown to themselves, referring to some idea that stands outside of space and time. I do think that there's a mind-independent world that gives us basic referents to represent. But the world is not cut at the joints (it doesn't come self-divided into identifiable objects) and is not self-interpreting (it does not represent itself to us). Thales, the first philosopher, certainly had a concept of water - he thought that everything in the universe was made of water. But despite the fact that the referent is the same, his concept of water is markedly different from our own. There is not an unmediated correspondence between the concept and the referent; hence the historical variability and contingency.