Platonism, fictionalism and all that

There was recently an interesting discussion of platonism and fictionalism as philosophies of mathematics.  This was at “The Electric Agora” blog.  I added a couple of comments myself.

Yesterday, I went back to take another look.  That was mostly to see if there were any additional comments.  And there were two, both by Robin Herbert.  But comments are now closed for that post.  So I’ll say something here.

First some links:

• First comment by Robin Herbert;
• Second comment by Robin Herbert.

Both comments add to the discussion and are worth reading.

Is fictionalism true?

In his first comment, Robin says:

So the argument that fictionalism must be true because the axioms are only conventions appears to make the same mistake as saying the truth or falsity of “if A then B” depends on the truth or falsity of A.

To me, this seems weird.  I have said that I am a fictionalist.  I have never said that fictionalism is true.  I’m not at all sure that I know what it would even mean to say that fictionalism is true.

Closing comments after 30 days

I’ve changed the settings on this blog, so that comments are automatically closed on a post after 30 days.

I’m making this change for two reasons:

1. There are too many spam comments, mostly on older posts.
2. I rarely get comments on old posts anyway.

For the present, I’ll leave all comments open on my other blog (on computer), because I do sometimes get comments on older posts there.