[FOM] Why inclusive disjunction?

[Máté András]

Two alternative answers:

1. The principle of minimal information (and minimal risk):
In the case of ambiguity, you should choose the minimal interpretation. 
(Reason: this strategy doesn't provide false information for the 
intrerpreter about what the speaker meant.) With exclusive and inclusive 
disjunction, the issue is rather simple: inclusive disjunction provides 
you less information, therefore "A or (inclusively) B" is what the 
speaker surely meant by saying 'A or B'. It is uncertain in most 
contexts whether he/she meant also "not (A and B)".
2. It is questionable whether  everyday language uses 'or' in exclusive 
sense at all. Let us construe the problem precisely: you say 'A or B' 
and I know FROM THE INFORMATION YOU GAVE ME ON THIS WAY that A and B are 
not both true. Does it happen? In the most examples for "exclusive 
disjunction" I know FROM ANOTHER SOURCE  that A and B are not both true. 
(For a more detailed argumentation see Benson Mates, "Identity and 
Predication in Plato".) It is true, however, that the language of 
statutes is not everyday language.

Bests,
Andras Mate
> I am preparing to teach a course in `proof'.
>
> Can anyone provide a principled reason for why logicians choose to
>  interpret "or" as inclusive disjunction?
>
> I understand that in the interpretations of statutes, the exclusive or
> is the default.  So attorney's have made a different choice of 
> `formalization'.
>
>
>
>
> John T. Baldwin



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