[ryanatau]

Quote by: Morality Games The idealistic philosophers (Plato) posulate the existence of a world of eternal forms (abstracts) from which the particulars of our universe derive. The Nietzchean assertion that abstracts are just the mind's comparison similarities of unlike things (observations of leaves create the impression of an abstract leaf in the mind) is more down to earth and sensible than supposing abstracts exist in another world.

You sort of misunderstand Plato. Regardless, Nietzsche (and other nominalists if you will allow me to call him that) do not quit say what you are saying because it does not destroy the Platonic argument. Plato would just say that the thing they are using to compare like things (the thing that makes them alike) are the forms. If the forms do not exist then there is not base to compare. What makes two leafs similar? Plato would say the forms. A nominalist might say the forms have no ontological being because that would suppose the forms are more real then the particular while in reality it is the particular and not the forms that exist. We abstract forms from the particulars but they have no ontological being.

I actually tend to agree more with Nietzsche. However, we have to ask what is the most fundamental piece of knowledge we have. An idealist would say thought is more fundamental then perception. Perception is less reliable. Whatever you personal belief is it is difficult to disregarded Descartes' Cogito as the first and most fundamental thing we know.

The mind, since it is just a way of describing the physical activity of the brain and other nerves, is a continuation of the world, not a world apart.

We are not sure whether the brain constitutes the mind. Your argument, I am sure, is that a person missing parts of their brain have decreased mental capacity. However, it could also be thought that the brain is the place that the mind and body connect (some what like Descartes postulated but with more sophistication). When part of the brain is missing the mind losses control of the body. I am not personally a dualist but it is a thought.