Professor Stone,

Thanks for trying to help.  I apparently need to clarify my problem here a bit.

The sentence/statement distinction is based on the notion of meaning as use, so that what a sentence means--the statement it expresses--is a matter of how it is used.  (This distinction shouldn't be attributed solely to Strawson, of course, as it goes back at least as far as Ryle's "Systematically Misleading Expressions," 1932).

It seems obvious that "the number of planets is greater than 7" is not normally used in the same way "nine is greater than 7" is used.  This is because "the number of planets" does not normally mean "nine."  Of course, we can say the number of planets is nine, but that is not to say that the two expressions mean the same thing.

For example, "the number of planets has changed" does not mean that the number nine has changed.  Also, if I ask if the number of planets is greater than seven, I am not asking if nine is greater than seven.  Further, a person can think that there are somewhere between 8 and 10 planets, and so say that the number of planets is greater than seven without meaning that the number of planets is nine, or that nine is greater than seven.

So I cannot agree with your claim that these terms ("nine" and "the number of planets") are both used to refer to the number nine.  Only in very unusual cases does "the number of planets" refer to the number nine.  (For example, if I am thinking of the number nine, and I tell you I am thinking of a number between one and ten, and you ask, "is it the number of planets?"  I can respond, "yes, I am thinking of the number of planets," and so mean that I am thinking of the number nine.)

And I cannot agree with your claim that the expressions "nine" and "the number of planets" add nothing to the statements the sentences express, and I'm afraid I don't understand what motivates your assertion here in the first place.  The statement our words express is how those words are used, and this usually depends somewhat on the words we use.

Regards,

Jason
Nov. 16, 2009