[FOM] Falsify Platonism?

[Oran Magal]

Dear Lucas, everyone,


> I started this thread with a rather innocent remark at
> the end of question. I would like to make a few remarkts.
>
> First of all, with 'falsify' I referred to science philosopher
> Karl Popper. The idea is that if there is no potential that
> a scientific theory can be falsified, you may question
> whether the theory means something. With this one can
> criticize the theory of the 'existence of God', since the
> followers of that theory do not give a way to falsify
> that theory. [...]

I think this is at once too narrow and too strong as a summary of
Popper's doctrine. For one thing, falsifiability was proposed as the
mark of a _scientific_ theory; the question of God's existence, or
that of the truth of any other traditional metaphysical question
(freedom of will, realism v. nominalism with regard to properties,
etc.) are not normally thought of as scientific questions. You may
want to say only scientific questions are genuinely meaningful; that
road has been taken more than once before. But this is a further,
quite strong claim, beyond Popper's doctrine (which you cite)
regarding the demarcation of scientific theories from
pseudo-scientific ones. (Popper's most famous examples of the latter
were astrology, psychoanalysis and Marxist dialectic materialism, I
believe.)


>
> Considering the fact that the group of experts on FOM, could
> not agree what could potentially falsify Platonism, I conclude,
> based on the philosophy of Karl Popper, that Platonism does
> not have much meaning.

I don't count myself an expert, but I do have two comments on this.
First, continuing my previous comment, one needs to consider
'falsification' more broadly if one wishes to apply it to the question
of realism regarding mathematics ("Platonism"). For example: "If a
metaphysical claim is to be meaningful, it must be formulated in such
a way that it would be possible to offer an argument that refutes it."
 - I'm not advancing this position myself, just trying to reconstruct
what I think you're getting at. If this is so far more or less ok, I
would offer the following: there are arguments such that, if one finds
them compelling, would cast doubt on a robust realist ("Platonist")
view of mathematics. This is about as strong as you can expect
'falsification' to be in metaphysics; decisive arguments that end a
centuries-long metaphysical debate once and for all are quite rare
animals.

I hope this was helpful.

Oran Magal
McGill Univ.