Platonism in a sentence as a noun

It is a philosophical stance which can be called platonism.

Here's a maybe useful excerpt from the Stanford Encyclopedia of Philosophy, "In short, where platonism is an explicitly philosophical view, working realism is first and foremost a view within mathematics itself about the correct methodology of this discipline.

Platonism definitions

noun

(philosophy) the philosophical doctrine that abstract concepts exist independent of their names

See also: Platonism realism