Friday, November 13, 2009

Vagueness

A guiding intuition in much of my thinking in metaphysics is that no vague fact is to be taken metaphysically seriously. I don't have an account of the seriousness, though. Still, the intuition has some nice consequences. Psychological theories of personal identity make diachronic identity vague—but diachronic identity should be taken seriously, so the theories are false. Materialism makes it vague where there is intentionality (because it makes all interesting macroscopic properties vague), hence materialism is false.

4 comments:

PFS said...

I really think that you've identified a fine criterion for identifying metaphysical seriousness (or even priority).

What about merelogical vagueness in which there are vague parts of an substance (eg., Tibbles the cat and the status of those hairs in which it is vague whether they are parts of Tibbles or not. Perhaps you could call them vague parts of Tibbles)?

On your criterion, it would seem that parts are less metaphysically serious than wholes since parts as a category of entities admit of vagueness whereas substances which are made up of parts do not. Of course, there are also vague objects which themselves are made up of parts, in that they do not have determinate identity conditions, or determinate existence conditions. I would suggest that if an object is a substance then it cannot itself be vague. This would suggest that objects also are less metaphysically serious than are substances. As I intimated above, metaphysical seriousness could somehow indicate metaphysical priority.

You could extend this even further and say that substances that are simple are more metaphysically serious than non-simple ones because they have no parts and so have no vague parts. Very nice.

Joshua Blanchard said...

Three questions.

(1) How exactly are you connecting the notion of taking something "seriously" to whether or not it is true or false? Is "seriousness" identical with some truth value or probability value? If something cannot be taken seriously, why is that sufficient justification for thinking it false?

(2) Since metaphysical positions might be clarified over time, wouldn't this criterion frequently yield bad decisions, frequently landing us on the wrong side of intellectual progress?

(3) Don't theories we accept - say, any view of personal identity, tend to make something that is otherwise "serious," vague? For example, any interactionist approach to the mind/body problem will likely give a vague account of that issue. Should all positions that require interactionism then be rejected?

Alexander R Pruss said...

PFS: Yes.

Joshua:

a. I don't know what the seriousness is.

b. I think it is much more common that something we thought was precise is in fact vague.

c. I don't see why interactionism has to be vague. I am using "vague" here in the technical sense in which there is a non-sharp boundary between the things that satisfy the concept and those that don't.

Doug Geivett said...

Does "seriousness" suffer from vagueness?

-Doug Geivett