Hylas’s Last Objection
The theory of immaterialism is inconsistent
with the creation story of the Christian
Bible.
According to immaterialism, objects
are just collections of ideas.
And ideas cannot exist apart from
being perceived by some mind.
So to create a thing is just to
create a collection of ideas in
the mind of some spirit.
But ideas cannot be created in God’s
mind.
(God is supposed to be eternal and
unchanging, so that whatever “archetypal”
ideas exist in God’s mind must be there
eternally)
So a creation of the world
would have to be a creation of
“ectypal” copies of God’s
“archetypal” ideas in human
minds.
But according to the story, God
created human beings last of all.
According to immaterialism, and contrary to
the creation story:
Human beings must have been the
first things to be created.
The creation must be ongoing,
involving the same activity now that it
did at first (indeed, more in
proportion to increases in the
population)
Berkeley’s Reply
“All objects are eternally known by God, or, which is
the same thing, have an eternal existence in His
mind: but when things, before imperceptible to
creatures, are, by a decree of God, made
perceptible to them; then are they said to begin a
relative existence, with respect to created minds.”
Some other species of finite spirits (angels)
existed prior to creation.
God’s act of creation involved “decreeing”
that different parts of the world
(different collections of ideas eternally
present in God’s mind)
should gradually become perceptible to
these spirits
(that “ectypal” copies of God’s
“archetypal” ideas should begin to be
created in the minds of these spirits)
A problem with this reply
The reply implies that in order for a thing to
exist, it is not sufficient that it be perceived
by God.
Because the existence of archetypal ideas in
God’s mind is not supposed to suffice for the
creation of things
But then Berkeley cannot appeal to
perception by God in order to explain what
people really believe when they believe that
objects exist in places where no finite spirit
is around to perceive them.
Nor can he present his theory as one on
which God’s existence is necessitated by
the belief in unperceived existence.
A modified Berkeleian solution
When we believe that vegetation exists in a
desert where no finite spirit is present, what
we really believe is that:
i. God perceives the vegetation
ii. God has “decreed” that, were any finite
spirit present, then it would perceive the
vegetation.
Further problems
Clause (i) is at best necessary, not
sufficient for unperceived existence. It is
the decree alone that suffices for the real
existence of the thing.
But this is tantamount to the counterfactual
account of unperceived existence.
Consequently:
The common sense perspective is
not preserved.
Things do pop in and out of
existence.
The only sense in which they
continue to exist unperceived is a
hollow, counterfactual one:
If someone were there, then they would get
certain ideas of sense.
What Berkeley Achieved
He presented the classic version of an
empirist theory of visual perception,
showing that much of what we think
we immediately or directly perceived
is in fact due to early learning and
unconscious inference.
He worked out an anti-realist,
instrumentalist philosophy of science
according to which scientific theories
do not tell us about the fundamental
constituents of reality, but merely
provide us with ways of calculating
what sensory experiences we will
have next.
He offered a powerful critique of
materialism and dualism, and a surprisingly
coherent vision of an alternative picture of
the world as consisting only of minds and
ideas.
His views shaped those of his most astute
immediate successors (Thomas Reid,
David Hume, Etienne Bonnot de Condillac,
Immanuel Kant), whose work was
developed in reaction to his own.
In particular, he forced them to think more
carefully about what a mind is, what an idea
is, and what it means for a mind to perceive
an idea.