On 29 Jan 2012, at 23:42, meekerdb wrote:

## Advertising

On 1/29/2012 7:47 AM, Bruno Marchal wrote:Math, even just arithmetic is already outside logicWhy exactly is that? Is it just because arithmetic has "..." in it,i.e. it posits a potential infinity of operations?

`Russell and Whitehead thought, like most of their contemporaries, that`

`elementary arithmetic can be deduced from logic. Today we know that it`

`is not the case, and we separate clearly the logical axioms (the`

`deduction means that we allow), and the non logical axioms, which`

`defines and assumes the non logical object we want to talk about`

`(numbers, strings, programs, sets, functions, etc.).`

Bruno 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.