The Topics of the Dialogues
Dialogues I & II:
Arguments against materialism
matter is unknowable
and impossible
Dialogues III:
Presentation of the theory of
immaterialism
and defence of the theory against
objections
Immaterialism
There are two kinds of things in existence:
 Ideas
(inactive, perceived things)
 Minds
(active, perceiving things)
Extension, colour, pain are all ideas.
(this has already been proven)
Minds can be nothing like ideas
and so must be unextended,
and hence indivisible
and naturally immortal.
Immaterialism, cont.’d
Ideas are of two kinds:
 Ideas of sense
(vivid, involuntary, orderly ideas)
 Ideas of imagination
(faint, voluntary, random ideas)
Immaterialism, cont.’d
There are also two kinds of language:
 ordinary language
 philosophical language
The ordinary language terms
“body”
“material being”
“real thing,” etc.
Name the same things that, in philosophical
language, are called
“collections of ideas of sense, commonly
observed to go together and referred to
by a common name”
The philosophical language terms
“body”
“material being”
“real thing,” etc.
name nothing whatsoever that anyone can
perceive or in any way come to know,
and nothing whatsoever that anyone can
even conceive
(insofar as they do name something
conceivable, e.g., mind-independent,
extended, solid, movable stuff, they name
something that cannot possibly exist)
What in ordinary language are called
fictional or unreal things (“chimeras”) are
either:
 ideas of imagination
or:
 false inferences
False inference
Real things = collections of ideas of sense
are not just collections of ideas coming
simultaneously from different senses.
The collections include different ideas coming from the
same sense at different times.
e.g., visual ideas of “the same object” (the same
named collection of ideas) viewed from different
distances
Not all the members of a collection are perceived at once.
Those that are perceived serve as signs for those that
might be perceived later.
Perceptual errors are not the result of perceiving unreal
ideas of sense
(all ideas of sense are equally real)
but rather drawing the wrong conclusions about what other
ideas are included in the bundle.
(When this happens we form ideas of imagination
that we take to be images of ideas of sense we
will get later, but that do not correspond to later
ideas of sense.)
Immaterialism, cont.’d
Because ideas are inactive, they cannot
cause one another.
(The only cause of ideas is minds, and it is not the
business of natural science to study minds.)
The job of natural science is to describe the
ways in which ideas of sense are ordered.
and, as far as possible, to show how
specific ways in which ideas are
ordered are merely instances of
more general regularities in the
succession of ideas
An event is “explained” scientifically by
showing how it follows from antecedent
events in accord with a rule, how that rule is
an instance of a more general rule, etc.
Immaterialism, cont.’d
There can be no true causality without
activity,
no activity without will,
no will without volition,
no volition without mind.
I obtain direct, intuitive, non-ideational,
“notional” knowledge of the existence of my
own mind as an active, willing thing through
“reflection.”
This reflection tells me that I cause ideas of
imagination through acts of will.
Immaterialism, cont.’d
I infer the existence of other minds by
reasoning from the existence of ideas of
sense, as effects, to the only cause I can
conceive of.
(and infer the existence of other
ideas of sense and imagination
perceived by those minds)
I cannot infer the existence of a material
substratum for qualities of extension and
solidity in this same way.
 because nothing gives me any notion of
matter
 because what I am told about it (that it is
an inert, unthinking thing in which ideas
inhere) makes no sense
 inherence of ideas in an unthinking
substance makes no sense
 causation of ideas by what is without
volition or will makes no sense
In contrast, perception of ideas by a
thinking subject does make sense,
as does production of ideas by volition of an
active subject
Immaterialism, cont.’d
Ideas cannot exist apart from being
perceived.
The “perceives” relation that obtains
between minds and ideas is unique.
In particular, it is not to be confused
with the “contains” relation or the
“inheres in” relation.
Consequences of Immaterialism
There is no distinction between appearance
and reality.
“… real things are those very things I
see and feel and perceive by my
senses.”
(misperception is explained as
above)
Those who draw a distinction between material and
sensible things,
and who take the material things to be real and the
sensible things to be appearances
are forced to:
 deny that we can know anything about real
things
 contradict common sense
 affirm that it is impossible that any real,
corporeal thing could exist
Consequences of Immaterialism, cont.’d
There is no distinction between primary and
secondary qualities.
Real things are collections of ideas
perceived by the senses.
These collections include ideas of
colours and other sensible qualities
as well as ideas of extension,
solidity, and their modes
(The two are in fact inseparable)
Consequences of Immaterialism, cont.’d
There is no distinction between the
existence of a real thing and its being
perceived.
Because real things are just
collections of ideas perceived by the
senses.
And for an idea to exist is for it to be
perceived.
For a real thing to exist unperceived can
only mean that it is perceived by some
other mind when it is not being perceived
by me
Or perceived by a divine mind when
there is no finite spirit around to
perceive it
In ordinary language, what it means to say:
“an object exists” is that
an object is perceived
“an object does not exist” is that
an object is not perceived
“an object exists away from me” is that
that object is perceived by some
other spirit
“an object exists where there is no finite
spirit around to perceive it” is that
that object is perceived by God
(though ordinary people may not pause to reflect on the
fact, their belief in the existence of objects in uninhabited
regions is bound up with a belief in the omnipresence of a
divine perceiver — only heathens and atheists attempt to
think otherwise by inventing the notion of matter)
Berkeley’s Argument for the Existence of
God
Sensible things are independent of my mind
So they have an existence exterior to
my mind.
So there is some other mind in which
they exist.
But sensible things have an existence
exterior to all finite, created minds.
So there must be an omnipresent,
external mind which perceives all
things and exhibits them to our view
in accord with the laws of nature.
Hylas’s Most Serious Objections
Bundle 1
(Problems with the “perceives” relation)
 God feels pain
 Extended ideas can’t fit in an
unextended mind
Bundle 2
(Problems with unperceived existence)
 Ordinary people think objects
continue to exist unperceived
 My ideas are different from anyone
else’s
Bundle 3
(Problems with notional self-knowledge)
 We are in no position to claim
notional self-knowledge
A Problem Case:
Pain
To feel pain is to be pained.
Pain is therefore as much a way in which a
mind exists as it is an “idea” perceived by
the mind.
This draws Berkeley’s distinction between
minds and ideas into question.
Some ideas (esp. pain and pleasure)
are states of mind,
that is, ways in which minds exist.
(Think what a large role the identification of ideas
with pleasure/pain plays in Berkeley’s argument.)
A Further Problem Case
Extension
Berkeley insisted that to feel extension is
not to be extended.
So that extension is at most a quality
of an idea and not a quality of a
mind.
But to feel pain is to be pained.
Are there two different ways an idea might
be perceived?
Does God Feel Pain?
When answering this question, Berkeley
maintained that there are in fact two
different ways of perceiving an idea:
 by “sensing” it
 by “understanding” it
God is supposed to “understand” pain
without “sensing” it.
Do we all just “understand” extension
without “sensing” it?
Some Problems
 Our ideas of tangible extension are not
separable from ideas of heat/cold or
pressure. But these ideas are just forms
of pleasure/pain.
So Berkeley can’t take perceiving (sensing) pain
to be a different thing from perceiving
(understanding) extension
 It becomes unclear how sensible things
can be perceived by God in our absence.
(Because sensible things are just collections of ideas
and the ideas that God understands are nothing like
the ideas that we sense.)
 If perceiving an idea involves being a
certain way, then it is clear that an idea
cannot exist apart from being perceived.
But if the mind is not affected by what it
perceives, then it is not obvious why the
idea should not be able to exist on its
own.
 If God can understand pain without feeling
pain, then there is a sense in which an
idea (understanding) of pain can exist
even though the object this idea
represents (sensed pain) does not exist.
So, in principle, having an idea is no
guarantee of the existence of the object of
the idea.
Berkeley’s Distinction Between Sensing
and Understanding an Idea
 We are just minds who do not have
corporeal sense organs. So how do we
distinguish “sensing” from
“understanding”?
Berkeley: ideas of sense are regularly preceded
by other ideas of sense (alterations in the
environment or the sense organs)
But the difference between sensing pain and
understanding pain is not just a difference in the
ideas that precede the occurrence of the pain
idea. It is rather a difference in whether you are
affected by the pain or not
Unperceived Existence
What does it mean for an idea to be
perceived by someone else when I do not
perceive it?
Answer 1: Ideas are public objects, existing
outside of all minds.
This is inconsistent with “esse est percipi”
Answer 2: Ideas are private objects,
existing only “in” (or “for”) the mind that
perceives them
(Given the opacity of the “perceives” relation, it is
unclear what “in” means.)
Then the real thing that is my collection of
ideas of sense is different from the real thing
that is your (or God’s) collection of ideas
My collection of ideas does not continue to
exist when I look away.
A (Malebrancheian) Answer
Suggested by Berkeley’s Argument for God’s Existence
Ideas of real things exist in God’s mind, not
in mine.
When God reveals these ideas to me in
accord with laws of nature …
… this doesn’t mean that God
creates copies (ectypes) of his
(archetypal) ideas in my mind
… it rather means that he lets me
look at the ideas that exist in him
Problems with this Answer
 God’s ideas aren’t at all like my own (see
above)
 When I perceive one of God’s ideas, I
must be altered in some way.
The alteration in me that consists in
my perceiving the idea must be
distinct from the idea (which is in
God)
But then in principle I could be
altered in this way even though the
idea does not exist
Another way of putting this: the idea,
insofar as it is anything to me, must
really be an alteration in me
An Alternative Answer
Identity is a fuzzy notion
A real object is a collection of ideas
commonly observed to go together and
called by a single name.
The collection does not just include
ideas of different senses and ideas
of imagination serving as images of
ideas that are had earlier or later by
the same sense
It also includes ideas of the ideas of
others, appropriately adjusted for
their different perspectives
An object can be said to exist
unperceived by me as long as others
have the appropriate ideas and use
the same name, even if those ideas
are not strictly identical.
A Problem with this Answer
Though the ideas of others need not be identical to
mine, they cannot be of just any sort whatsoever,
particularly as regards ideas of primary
qualities.
I envision other minds to occupy locations in space
outside of me and to perceive 3-D objects in the
common space between us from different
perspectives.
An application of perspective geometry to my ideas
of the shape and position of the object leads me to
deduce what ideas of primary qualities are
appropriately experienced by others.
Consequence: I can’t begin to formulate what ideas
are “identical” without presupposing an external
world containing public objects that determine what
ideas are experienced by others.
My practice therefore contradicts my theory.
Notional Self-Knowledge
Hume’s objection:
(echoed by Hylas)
Let me “reflect” as closely on myself as I
want,
I never discover anything but a
constantly changing ideas
Even when experiencing myself as
willing, I only discover volitions, which
are a kind of idea …
… and which are at best regularly
(though not invariably) correlated
with effects
Berkeley’s Answer
A colour cannot perceive a sound or a
sound a colour.
In general, an idea cannot perceive another
idea.
So there must be something else besides
ideas that perceives them.
This thing is what we call a mind.
Hume’s Reply
(not echoed by Hylas)
Each simple idea is complete unto itself,
lacking nothing for its existence
(a colour point can exist apart from a
sound or apart from any other idea and
so lacks nothing that I can conceive in
order to be able to exist)
If you say an idea cannot exist apart from a
mind, I ought to be able to conceive what
you mean by “mind” and feel compelled to
add that thing into the idea of a colour point
as a condition of forming the idea.
But there is nothing that is meant by the
terms “self” or “mind,” so nothing that can
be added.
(A notion of myself would have to be a notion of
something that is with me every moment of my
existence. But I have no such notion.)