[FOM] Frank Quinn article in January Notices

[Monroe Eskew]

On Dec 27, 2011, at 9:44 AM, "Timothy Y. Chow" <tchow at alum.mit.edu> wrote:
> 
> By "excluded-middle reasoning," I think Quinn does *not* mean
> 
>  the principle that if we know that "not P" is false, then we know
>  that "P" is true
> 
> but rather
> 
>  the principle that we cannot know that "P" is true unless we can
>  prove that "not P" cannot be true.
> 
> With this definition, I think we can recognize the principle as being 
> something that is standard among mathematicians but foreign to most 
> others.
> 

On page 34, at the beginning of the section, "Hilbert's Missed Opportunities," Quinn explicitly defines excluded middle reasoning as proof by contradiction.  I think Chow's interpretation cannot be correct.

Best,
Monroe