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sequence in turn license a sorites argument, and yield the
paradoxical consequence that the familiar object, which orig-
inally we think of as characterized by causal looseness of
knit, is not characterized by anything since it does not exist?
6.3 Degrees of Truth as Qualifying the Compositional
Vagueness of Actual Familiar Objects
The answer, I suggest, again lies in the way the familiar
object s essential properties supervene on what is done, at
126 Chapter 6
the level of microphysics, by its component microparticles.
They supervene on loose-knit causal interactions done by
these microparticles interactions that the microparticles do
between them, but not in concert. But supervene they do. So
it cannot be perfectly true that, as a general matter without
qualification, removal of any one component microparticle
leaves the essential properties still present leaves the
familiar object still existing. The idea that a familiar object
is compositionally vague must have a great deal of truth,
but cannot be perfectly true.
If the general thesis of compositional vagueness is less
than perfectly true, then, so will substitution instances of
that general thesis be less than perfectly true. If B is a
bicycle, then B-minus-one-microparticle is a bicycle will be
less than perfectly true. Then even if its antecedent is per-
fectly true, its consequent may be less than perfectly true.
Similarly, if B-minus-one-microparticle is a bicycle, then B-
minus-two-microparticles is a bicycle will be less than per-
fectly true. It may join an antecedent that falls just short of
perfect truth to a consequent that falls short by a slightly
greater margin. And if we conjoin a huge series of such
conditionals, and treat material implication as transitive
which is just what a sorites of decomposition argument
does we may at length arrive at a detached consequent
which is false. B-reduced-to-a-single-molecule is a bicycle can
then be simply false.
There is, therefore, a way of admitting that familiar objects
such as bicycles can (if real at all) survive the loss of a single
microparticle, without having to concede that bicycles can
be shrunk to the size of a single molecule and hence
without having to deny that there are bicycles in the first
place. It requires merely the idea that statements about
familiar objects need not be true or false simpliciter, but can
A Response to Compositional Vagueness 127
be true to a greater or lesser degree, and shade off gradu-
ally into falsehood.
6.4 Degrees of Truth versus Epistemicism
Thus the defense of familiar objects that I offer, against
the sorites of decomposition, relies on a general strategy that
is already familiar (Williamson 1994, ch. 4; Keefe 1999). It is
familiar that degrees of truth can be used to resist sorites
arguments of various kinds. One can, for example, hold that
it is not perfectly true that if a man is rich, reducing his wealth
by a penny leaves him rich still, and thus can avoid a sorites
that would yield the conclusion that even a man who has
only two cents is rich, if anyone is; so likewise for sorites
arguments about baldness, tallness, or heaps. But familiar-
ity here is as much a curse as a blessing. It is well known
that all familiar ways of responding to sorites arguments
face substantial objections. I will not undertake here to
discuss the objections the worst of them concerns truth
functionality against the degrees of truth approach.1 I
will say only that however substantial the objections may
appear, degrees of truth offers us the brightest prospects
for preserving familiar medium-sized objects in our ontol-
ogy. And preserve them we must, as chapter 8 will argue.
Many readers, I realize, will suppose that the epistemi-
cist approach to vagueness offers at least equally bright
prospects for preserving familiar objects. Epistemicism
holds that as we run through the sorites taking pennies from
a rich man, or the sorites removing individual microparti-
cles from a bicycle, we do reach a precise point at which sub-
tracting just a single penny more will render the rich man
rich no longer, and removing a single microparticle more
will destroy the bicycle (Markosian 1998; Sorensen 1998,
128 Chapter 6
p. 275, or 1988, p. 10; cf. Williamson 1994). We merely do not
know, the epistemicist says, where this precise point lies. But
what 6.2 and 6.3 have argued is that this is precisely the
picture of a bicycle, or of any other familiar object, that plays
directly into the hands of causal exclusion arguments. If
epistemicism saves familiar objects for serious ontology,
it save them only to be destroyed by causal exclusion. So I
hold to my claim: some version of the degrees of truth
position must be defensible, since in all likelihood the truth
of this position is required by the claim that some familiar
objects exist, and that is a claim to which we simply are
forced to subscribe (chapter 8).
Toward a Robust
III
Common-sense
Ontology
Artifacts and Other
7
Copied Kinds
Suppose that a carpenter shapes pieces of wood and
arranges them together so as to compose a desk. In onto-
logical strictness, what has happened? Is it just that certain
pieces of wood or bundles of cellulose fibers have gotten
arranged differently toward one another, or has some object
different in kind from either the pieces or the bundles been
created? Suppose that the desk gets crushed, perhaps by a
collapsing roof, and no longer can function as a desk. Is this
just a matter of certain objects being set in a new arrange-
ment perhaps very small objects, for example, cellulose
molecules, if the crushing is severe or is it a matter of some
one object s being destroyed?
Many, many contemporary metaphysicians (as we have
noted) find it hard enough to believe that even the pieces of
wood out of which the carpenter fashions the desk really
exist in ontological strictness. For even the pieces of wood
appear to give rise to the worries about causal exclusion
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