Rute asked:

Is idealism the same as anti-realism? If not, What is the difference?

and Alan asked:

I have a question: do you think it is right to try and link realism/ anti-realism about truth to the
philosophy of language and theories of meaning? I have been pondering this one for a while. I agree
that when you say something is true, you can only mean that words have been used correctly or not.
Is this subjectivism or is truth something else?

============

Part of this question has been dealt with in my answer to Johanna, on the eighth page of questions
and answers.

I would characterize idealism as a theory concerning the nature of existenceand anti-realism as a
theory concerning the nature of truth. You can hold, or reject, either or both theories, so that there are
four possible permutations altogether.

According to Berkeley's idealism, what we term 'material objects' are really ideas existing in the mind
of God. To exist is to perceiveor to be perceived. The entire universe consists in God — or, rather,
God's infinite mind — and the finite 'spirits' that God has created, namely us. To use contemporary
language, material objects like this desk or this keyboard, or the hands that I see typing these keys,
exist in a 'virtual reality'.

In his paper 'The Reality of the Past' (reprinted in Truth and Other Enigmas) the British philosopher
Michael Dummett describes a theory which rejects the view that statements about the past for which
there is no effective decision procedure still havea truth value. The claim can be made about any
subject matter. The past provides a particularly clear example. As the poet John Donne once wrote,
in his 'Song':

Go and catch a falling star,
Get with child a mandrake root,
Tell me where all past yeares are,
Or who cleft the Divel's foote...

Where are past 'facts', if there's no Recording Angel? If you believe that the truth is 'back there'
irrespective of whether or not we can ever know about it, then you are a realist.

In these terms, Berkeley was a realist. He believed that the answers to questions about the past exist
in God's mind even though we might never come to know those answers. By contrast, Dummett
rejects Berkeleian idealism. He embraces the existence of material objects existing apart from the
mind and its perceptions.

Much of my doctoral thesis was spent attacking the view that anti-realism is a thesis about the nature
of meaning, and not just a thesis about the nature of truth. Talking to philosophers today, it is clear
that the penny has still not dropped. There are in fact two claims which Dummett defends:

*
Anti-realism entails a theory of meaning according to which the central concept is not that of truth but
verification. The meaning of a statement is notits truth conditions, where truth is understood to be a
property which a statement can possess regardless of our capacity to determine that it has that
property. To know the meaning of a statement is simply to know the rules for its correct use.

*
Anti-realism entails the refusal to accept the truth of the Law of Excluded Middle, P or not-P. It
follows that the anti-realist must reject Classical logic.

Defenders of anti-realism who reject claim 1. still cling to claim 2. In other words, they still cling to the
idea that there has to be some practical upshotof the rejection of realism. There must be something,
they believe, that the realist is prepared to say (like 'Either Caesar thought of his father before
crossing the Rubicon or he did not') which the anti-realist is not prepared to say.

They are wrong. The anti-realist is perfectly capable of making that statement. The anti-realist merely
associates a different picturewith the assertion of the excluded middle from the picture which the
realist associates with it.

In that respect, anti-realism and Berkeleian idealism are on a par. There is no statement about the
worldwhich the idealist makes which the opponent of idealism is not prepared to make, or which the
opponent of idealism makes which the idealist is not prepared to make. Idealists don't differ from in
their empirical beliefs, or in their commitment to science. They don't differ in their logic. They don't
differ in their theory of meaning. Like anti-realists, they differ in their metaphysic.

Geoffrey Klempner