Thursday, February 18, 2016

Why reference matters

Graham Oppy writes:

At 368, Reppert argues: If the reference of our terms is indeterminate, then this has the disastrous consequence that we cannot reason to conclusions.
This is surely wrong. Reasoning can be purely formal. (If all flombs are bloops, and all bloops are shimbs, then all flombs are shimbs. The reasoning is impeccable. We can reason even if our terms have no meanings!) Moreover — and perhaps partly in consequence — so long as we restrict ourselves to a single context, and use the same word throughout, we can reason perfectly well even if our meanings are indeterminate. (If this is a rabbit, and that is a distinct rabbit, then there are at least two rabbits. Fine, regardless of Quinean indeterminacy in the meaning of “rabbit”!)

VR: But that's just the problem. Without fixed reference, we don't know whether we have three terms, four terms, five terms, or six terms. 

Let's take the following argument. 
1. All jackrabbits are gavagais. 
2. All gavagais are mammals. 
3. Therefore all jackrabbits are mammals. 

This argument is valid if the reference of gavagai is invariant between premise 1 and premise 2. But what if in premise 1 gavagai means "rabbit", but in the second it means "undetached rabbit part." Then the argument is invalid. 

4 comments:

Hugo Pelland said...

This is very interesting, but I think that being 'indeterminate' does not mean that the law of identity is violated, which is what this implies: "But what if in premise 1 gavagai means "rabbit", but in the second it means "undetached rabbit part."" The reasoning is valid regardless of what 'gavagais' means, but not at the expense of the term referring to different things; this is what the example "If all flombs are bloops, and all bloops are shimbs, then all flombs are shimbs" implies. So, even when keeping the terms indeterminate, we can reason by explaining just that: the argument is valid iff 'gavagais' or 'flombs' or 'bloops' or 'shimbs' are a unique thing, or set of identical things, as to not violate the law of identity.

Joe Hinman said...

Hugo, I find your argument perfectly comulent.

IlĂ­on said...

VR: "If the reference of our terms is indeterminate, then this has the disastrous consequence that we cannot reason to conclusions."

Graham Oppy: "This is surely wrong. Reasoning can be purely formal. (If all flombs are bloops, and all bloops are shimbs, then all flombs are shimbs. The reasoning is impeccable. We can reason even if our terms have no meanings!)
"

VR: "But that's just the problem. Without fixed reference, we don't know whether we have three terms, four terms, five terms, or six terms."

Is Mr Oppy's syllogism *really* an act of reasoning? He says, "The reasoning is impeccable". I say that it's the logic that is "impeccable" -- assuming that the terms are non-equivocal (which is VR's point in this blog entry), but the no reasoning has occurred.

oozzielionel said...

The most difficult term may be "are."
https://www.youtube.com/watch?v=j4XT-l-_3y0