FOM: Butz on truth

[John Mayberry]

	Carsten Butz asks "How can anyone claim that there is absolute 
truth out there?". Well, I am not happy with the adjective "absolute" 
because it suggests that truth is something that admits of degrees, and 
that can make sense only if it is taken metaphorically. But with that 
qualification I am perfectly willing - indeed, I am compelled - to 
make such a claim.
	Butz's view is absolute nonsense (and in this case I use the 
adjective without any hesitation whatsoever). It is absolute, 
double-dyed nonsense in the mouth of a mathematician. For 
mathematicians deal in proof; and a proof is a valid argument to 
establish that its conclusion is a true proposition. If there is no 
such thing as truth, then there is no such thing as proof. And if there 
is no such thing as proof, then there is no such thing as mathematics, 
*a fortiori* no such thing as a foundation for mathematics. Here we 
witness the spectacle of a man sawing off the very limb on which he 
himself is perched.
	Told of a similar species of absurdity, Dr. Johnson replied 
"Why Sir, if he really believes that there is no difference between 
vice and virtue, when he leaves our houses let us count our spoons". Of 
course, a man who does not believe in truth does not believe in 
differences of any sort. Indeed, he cannot believe in anything at all, 
for to believe a proposition is to believe that it is *true*. 

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John Mayberry
Lecturer in Mathematics
J.P.Mayberry at bristol.ac.uk
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