Some 30 years ago, I submitted an article with this title to a journal in mathematical education. It was rejected. And mostly unread -- as I ascertained from the glued pages which remained stuck together. I'LL briefly articulate its THESIS.Historically, PLATONISM is associated with the philosophy of UNIVERSAL IDEAS. Take the concept of a circle. No one has ever SEEN A CIRCLE. A magnification readily shows both "wobbles" and GAPS in its ARCING -- quite UNCIRCLELIKE. Yet a considerable number of persons can be shown to agree on the same "approximation" as "a circle". Wherefore, prithee?
Plato (x-y) and many followers of his time and since have argued that certain UNIVERSALS do not exist ON EARTH, but exist in a HEAVEN FROM WHENCE WE CAME. There, we experienced these IDEAS (circles, et al), and REMEMBER THEM ON EARTH.
When I was struggling with "Calculus", a friend of my wife said, "Everyone could remember Calculus if only they meditated enough." She said she didn't have time for this, but was certain she could do so if she found the time. But, no matter how much I meditated, I couldn't remember CALCULUS and other suchies.
Since I can't subscribe to this "heavenly" explanation, I accept the challenge of offering an alternative.
Hypothesis: Evolution provided us with a BRAIN-PROCESS HOMOLOGOUS TO THE LIMIT PROCESS IN MATHEMATICS -- GETTING "CLOSE ENOUGH" TO ACCEPT THE "THINGY". Dig or Redig.
Howsomever, the above isn't THE SCARY PART!!!
There developed the philosophy that ONLY UNIVERSAL IDEAS EXIST!!! If you and I exist, it's only as SURROGATE FOR AN IDEA or INSTANCE OF A UNIVERSAL IDEA. Sowhat?
What about "killing" an INSTANCE OF AN IDEA? Is this murder? Is it immoral or unethical?
This is "The Subspiracy" behind the PLATONISM of "The New Mathematics". A "subspiracy" because I judge it to be "a subliminal conspiracy".
But -- until devout Platonists, such as The Bourbaki and Roger Penrose, sign a DISCLAIMER OF SUCH INTENTIONS -- I'll continue to look over my shoulder! Dig or redig.