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Topic: Is it possible that 3+4=8?
Replies: 21   Last Post: Jan 29, 2011 9:06 AM

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Posts: 910
Registered: 3/9/08
Re: Is it possible that 3+4=8?
Posted: Jan 24, 2011 7:26 AM
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On Jan 24, 11:02 am, LudovicoVan <> wrote:
> On Jan 23, 8:31 pm, LudovicoVan <> wrote:

> > On Jan 23, 7:47 pm, Craig Feinstein <> wrote:
> > > [...]
> > > In our real world, it is a known fact that 3+4=7. But how can we be
> > > sure that there are no invisible pixies running around taking balls
> > > away from us causing us to think that 3+4=7 when really 3+4=8?

> > > My point is that mathematics is considered a deductive science, in
> > > which everything is absolutely certain. But how can mathematics prove
> > > that the above scenario cannot be true?

> > I don't think mathematics is a deductive science: mathematics is
> > hardly a science at all. OTOH, in a world were 3+4=7, I'd also expect
> > 1=/=0: i.e. no mathematical fact exists in isolation...

> Thinking: It is logic that grounds mathematics, i.e. it is logic that
> gives mathematics its initial premise and final validation.
> -LV

How can that be, if Mathematical Logic is a branch of mathematics ?
It is NOT logic that grounds mathematics. It is rather mathematics
that grounds logic. (And physics grounds mathematics, but that is ..
quite another story)

Han de Bruijn

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