These are the answers by physicist
Marni Sheppeard 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?
Yes.
Brouwer was right.
-
Do you agree that the intermediate value theorem does not
hold the way that it is normally stated?
Yes.
-
Do you agree that there are only three infinite
cardinalities?
Mu.
Depends on the topos you live in.
-
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?
No.
It is an independent axiom outside of an internal notion of truth.
-
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?
No.
-
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?
No.
Certainly not!
-
Do you agree that for any two statements the first
implies the second or the second implies the first?
No.
Certainly not.
-
Do you agree that a constructive proof of a theorem
gives more insight than a classical proof?
Mu.
Classical proofs are often much more elegant, but there is the
possibility of deeper insight with constructivism, and then it depends
on the case....
-
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?
Yes.
Truth is contextual, and some kinds of truth have a higher
level of truth (in a category theoretic sense) than others.