Introduction to Metaphysics

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Introduction to Metaphysics Alexander Bird
What is Time?
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John McTaggart on the unreality of time
two ways of expressing temporal properties and
relations
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A-series
tensed
1-place properties
relate to the present
B-series
untensed
2-place properties (relations)
independent of present
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McTaggarts argument for the unreality of time

• Change is essential to time
• Change is possible only with the A series
• The A series is incoherent (self-contradictory)
• therefore
• C. Time is impossible (and so does not exist)

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Is change essential to time?
Philosophers dispute whether change is essential
to time. (Could there be a world in which time
passes but nothing changes?)
But in fact McTaggart needs only the premise
that the possibility of change is essential to
time
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Is change possible only with the A series?
x is F before t x is not F after t
does this suffice for change?
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Is the A series is incoherent?
McTaggarts argument an event will have
incompatible A properties
e.g. a future event is future, will be
present, and will be past
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Some responses
B theorists The A series is incoherent ?
there are no genuine A properties ? A
properties are reducible to B relations
t is present t is simultaneous with now t is
future t is later than now
now is an indexical (like here)
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A theorists The A series is coherent there are
genuine, unanalyzable A-properties A-properties
are not reducible to B-relations
take tense seriously
is present and will be past are genuine
properties whose tensed character is ineliminable
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Relativity theory and time
A theorists A-properties are genuine (natural)
properties, e.g. is present
but Einsteins special theory of relativity tells
us that there are no objective facts about
simultaneity
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here, now
possess the natural property is present
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Presentism
Only the present exists (only presently existing
entities exist)
You and I exist Socrates does not exist
In Socrates day, he existed, but we did not
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problems for presentism
presentism can be seen as a version of the A
theory it is thus vulnerable to the special
relativity objection to the A theory
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Helena Bonham Carter is great-granddaughter of
Herbert Asquith
Can this relation hold if one of the relata does
not exist?
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future
present
past
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further reading
D. H. Mellor Real Time II R. Le Poidevin and M.
McBeath (Eds) The Philosophy of Time