These are the answers by computer scientist
Jacques Carette to the
ten questions about intuitionism:
-
Do you agree that it is impossible to define a total
function from the reals to the reals which is not
continuous?
No.
It depends on your underlying theory.
-
Do you agree that the intermediate value theorem does not
hold the way that it is normally stated?
No.
It depends on your underlying theory.
-
Do you agree that there are only three infinite
cardinalities?
No.
There are as many infinite cardinalities as you want!
-
Do you agree that the continuum hypothesis is a
meaningful statement that has a definite truth value,
even if we do not know what it is?
Mu.
It is a meaningful statement of some theories. In some theories, it
even has a definite truth value.
-
Do you agree that the axiom which states the existence
of an inaccessible cardinal is a meaningful statement
that has a definite truth value, even if we do not know
what it is?
Mu.
It is a meaningful statement of some theories. In some theories, it
even has a definite truth value.
-
Do you agree that for any mathematical question it is
easy to build a machine with two lights, yes and no,
where the light marked yes will be on if it is true
and the light marked no will be on if it is false?
Mu.
-
Do you agree that for any two statements the first
implies the second or the second implies the first?
Mu.
I believe that for any two defined statements this is true, it
is false for non-denoting statements.
-
Do you agree that a constructive proof of a theorem
gives more insight than a classical proof?
No.
It may or may not, depending on the theorem!
-
Do you agree that mathematics can be done using different
kinds of reasoning, and that depending on the situation
different kinds of reasoning are appropriate?
Yes.
-
Do you agree that all mathematical truths are true,
but that some mathematical truths are more true than
other mathematical truths?
No.