The following diagram is from a lecture entitled Science and the Mind given by Dr. Roger Penrose* through the Institute for Theoretical Physics in December of 1999 and represents a conundrum in any Platonistic/Idealistic view of the world.
(* -- The analysis and views presented below are entirely my own and not those of Dr. Penrose)
The problem goes like this: Plato proposed that the physical world with all its change and specificity was a shadow of an ideal world. In the ideal world exists all the perfect unchanging models of the things we encounter in the real world. This explains how we can have an idea of a horse when we only know specific horses, no one of which embodies all the attributes of the idea of a horse. This vision of an ideal world is an idea itself -- part of the mental furniture of the mind of Plato and others. And while the mind seems to be an outgrowth or manifestation of the physical world (at minimum you'd have to agree that your mind is somehow in the physical world), the mental world of the mind seems to by no means be reducible to the physical world (say to the organ of the brain).
Thus the whole project of idealism appears to be circular and tri-partate. The physical world manifests mind. Mind manifests ideals. And ideals manifest the physical world.
This applies as well to any system in which a formal ideal system is said to describe or embody the essence of the physical world (assuming the physical world also contains the mind that develops the system). This is precisely the conundrum of all science -- in which mathematics is used to formally describe reality. It is even more true of Quantum Mechanics (QM) since QM is a formal system that well describes the physical world but which has no analog in the physical world to which to point as did classical physics. QM is all and only mathematical formalism. How that formalism is related to the physical world is an unsolved problem.