If you think that the blog's point was to openly discuss the arbitrarity of certain definitions, then you have read another blog than I did. Given the blog's ob

If you think that the blog's point was to openly discuss the arbitrarity of certain definitions, then you have read another blog than I did. Given the blog's obvious agenda, I find it a bit disingenious to summarize it like you do. The new definition of 'planet' is meant to capture the set of bodies that are the most significant, dominant or prominent bodies in the Solar System. And under the current definition, this is captured perfectly, and will work well in the Solar System for the next billion years at least. While I agree that the definition is not perfect and ultimately arbitrary, our categorization of things should be helpful. Given their vastly different influence on the Solar System, a categorization in which Venus and Jupiter are distinct from Sedna and Ceres is more helpful than one in which they are the same, in my opinion.