Introduction to Metaphysics

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Introduction to Metaphysics Alexander Bird
What is metaphysics?
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my webpage eis.bris.ac.uk/plajb/
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metaphysics is the study of the most general
features of our world
what is required in order to give a complete
description of the world?
an inventory of the worlds entities an
account of how they combine
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1. The world is everything that is the case. 1.1
The world is the totality of facts, not of
things. Tractatus Logico-Philosophicus
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Introduction to Metaphysics
What are things?
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what kinds of objects exist?
simple objects fundamental particles?
space-time points? complex objects an atom? a
tennis racket? my family? abstract objects
numbers and sets?
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which complex objects exist?
mereology the theory of the relation between
parts and wholes
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which complex objects exist?
unrestricted mereological composition for any
objects, a, b, there is a further object a
b (the fusion of a and b) of which a, b are
parts
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unrestricted mereological composition
can items separated widely in space and time form
a whole? (families? nations? species?)
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unrestricted mereological composition
the fusion of a and b necessarily has a and b as
parts but most objects can lose some parts and
continue to exist
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how many objects?
seemingly one table but how many parts?
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count under a sortal
how many tables? (not how many objects?
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how many mountains where Everest is?
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many mountains? (which one is Everest?) or one
mountain? (which is its boundary?)
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could there be just one mountain which is a vague
object?
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vagueness

• there is a precise boundary, but we can never
  know which it is (epistemicism)
• there is no precise boundarythe objects is
  itself vague (ontic vagueness)

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Evans problem for ontic vagueness
ontic vagueness requires vague identity
a and b are vaguely identical but a and a are
precisely (definitely) identical, not vaguely
identical Thus a and b have different
properties hence a and b are (precisely)
non-identical.