FOM: ``arbitrary objects"

[Arnon Avron]

I should say that I find the discussion about "arbitrary objects"
(or "arbitrary numbers") rather embarrassing, especially that
it is made by logicans. When I read it I got the feeling that
Gentzen (and his analysis of Natural Deduction) and Tarski
(with his semantical analysis of formulas, using structures
and assignments) had never existed, and that 
variables and their correct use are still a mystery...

Arnon Avron