Hi, What do you mean by Platonia?

## Advertising

`The kind of Platonia in Tegmark or in Peter's (1Z) post does not make`

`sense for mathematicians. Even if you are using a theory like Quine's`

`NF, which allows mathematical universes, you still have no`

`mathematical description of the whole mathematical reality. Tegmark is`

`naïve about this.`

`*Arithmetical* platonia can be said to exist, at least in the sense`

`that you can prove it to exist in models of acceptable set theories,`

`like ZF. It is just the structure (N, +, x). It is used in all papers`

`in physics, math and logic, including Pratt ...`

`Now, with computationalism, we don't even need such a mathematical`

`arithmetical Platonia. We need only the idea that arithmetical truth`

`(even a tiny effective part of it) is independent of you and me. Like`

`in Plotinus, the ultimate being (arithmetical platonia) is not a being`

`itself (nor is matter!).`

`So neither Platonia, nor even arithmetical Platonia needs to exist.`

`Numbers needs to exist in some sense, and do exist in theories like RA`

`or PA, in the sense that such theories formally proves that Ex(x =`

`sssssss0) for example.`

Just to be a bit precise. Bruno On 18 Feb 2011, at 02:49, Stephen Paul King wrote:

Hi All, Question: Why must Platonia exist? Onward! Stephen“It is amazing what can be accomplished when nobody cares about whogets the credit.”Robert Yates --You received this message because you are subscribed to the GoogleGroups "Everything List" group.To post to this group, send email to everything-list@googlegroups.com.To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com.For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.

http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.