Look around the room. You probably see a desk, chairs, and some books. You believe that all these
things exist. Moreover, you believe that they exist in such a way that corresponds to your percepton
of them. If someone told you that, in fact, nothing in the room existed except for you, you would
dismiss this person as a lunatc. This is because you are not a skeptc. You believe in the real
existence of the objects of your experience. Berkeley would applaud you; according to his
philosophy, you have common sense.
But there is probably also something else that you believe about the things in your room. You
believe that they exist independent of any perceivers. That is, you think that, even if there were no
one at all perceiving these things, they would contnue to exist. You think that they are independent
of human minds. This is where Berkeley would disagree with you. In fact, he goes so far as to say
that your commitment to this belief runs counter to common sense. This is because he thinks he can
show that your commitment to the existence of mind- independent objects will lead you to reject
the above two common sense commitments that you and he share: that desks, chairs, books, etc.
really exist and that they exist in such a way that corresponds with our percepton of them. His
mission in the Three Dialogues is to prove this to you.
Berkeley breaks his book up into three separate sectons, or dialogues. In the 1 st dialogue he tries to
demonstrate that materialism — or the belief in the existence of mind-independent material objects
— is incoherent, untenable, and leads ultmately to sceptcism. In the following 2 dialogues he
attempts to build up his own alternatve worldview, immaterialism (now known as idealism..
According to this view all that exists in the world are ideas and the minds that perceive them,
including the infnite mind that contains all else, namely God. In the 2 nd dialogue he lays this picture
out, and in the third he flls in some details and defends it against possible objectons.
In broad outline, Berkeley's argument against materialism goes like this: (1. If we perceive mind-
independent material objects, then we either perceive them immediately (through our senses. or
mediately (by inferring them from what we immediately receive through our senses.. Berkeley
believes in this claim because he is an empiricist, that is, someone who believes that all knowledge
comes through the senses. If the only way we have of getng knowledge is though the senses, then
these really are our only two optons for coming to know about mind-independent material objects.
(2. We do not immediately perceive mind- independent material objects. (3. We do not mediately
perceive mind-independent material objects. (4. We have absolutely no reason to believe in the
existence of mind-independent material objects. The conclusion of this argument is not that mind-
independent material objects do not exist; it is that we have no reason to believe that they exist.
Berkeley thinks that this conclusion is strong enough; if we have no reason to think mind-
independent material objects exist, then we should not believe that they exist. However, Berkeley
does think that several of the arguments he uses along the way, to prove the second and third
premises, actually do show conclusively that mind-independent material objects cannot exist.
Prominent among this latter group is an argument that has come to be known as the Master
Argument. This argument is intended to show that the very idea of an object existng outside of the
mind is inconceivable. It is impossible to conceive of an object existng without the mind, goes the
argument, because the second you try to do so, the object is in your mind. Just by trying, in other
words, you fail! This is actually a terrible argument, and some philosophers go so far as to say that it
is no argument at all. (The Australian philosopher David Stove likes to call it "the Gem"..
Nonetheless, it has been widely infuental in the history of philosophy, and Berkeley himself seemed
to like it a great deal.
After undermining the claims of materialism, Berkeley next moves on to present his own
immaterialist picture. According to this view, real things, things like desks, chairs, and books, are just
collectons of ideas that exist in the mind of God. God sometmes exhibits these to us, and we