Struggling with understanding Platonic idealism and idealism in general

Question

I probably incorrectly understand some basic things, so I'll show my layman thinking process for easier identification of where lies the problem.

Let's start with basic dichotomy - materialism vs. idealism of what's more primal - matter or mind. As far as I understand, idealism operates only on concepts of human mind and perception thus it's strictly anthropocentric approach.

As materialism states that only matter ontologically exists, idealism states that only ideas (i.e. human cognitive apparatus and perception) ontologically exist.

Thus if we want to stick with idealism, we fall into correlation loop - we are constricted by the ideas we are able to think, as if we assume something that we can't think, it automatically becomes thinkable.

So if idealist wants to say that some object "exists" that would mean something like "we are able think that this object exist (exist in intersubjective consensus reality)".

Then Plato's states his Forms - entities that are not material objects (thus, it's not a materialism), but also not a results of human mind, as they ontologically exist, independent from our cognition. So why is it idealism? Forms doesn't fall in any category of mind and matter. Is it implicitly assumed that Form are results of human cognition? In another words, who thinks the Forms for them to exist in idealistic approach?

As far as I understand, by Plato "actual" reality constitutes only from Form, by they are inaccessible by any meaning. Would it be correct to say that the Form might as well not exist at all from this standpoint?

Why does Platonism falls into a mathematicism category? If we say that everything is math concepts, not correlated with human perception and cognition, wouldn't it be a materialism?

Answer 1

As the term 'idealism' is used in epistemology and metaphysics there is nothing common and distinctive to all forms of idealism except the claim that reality is non-physical. This accommodates Berkeleley's view that all that exist are immaterial minds and their ideas. It also fits with Plato's theory of Forms, where the Forms are pure essences (e.g. the Form of the Beautiful is alone really beautiful) transcendent of the physical world although the physical world 'participates in' or 'imitates' the world of Forms.

Mathematical 'platonism' holds that immaterial mathematical objects such as numbers and sets exist independently of the human mind. (Apologies to mathematicians, who can state it better.)

Your question raises the whole issue of the role of classifications ('labels') in philosophy: idealism, empiricism, realism, antirealism, pragmatism, conceptualism, &c. I think it is far better to establish what a philosopher holds exactly than to see what classificatory box s/he fits into. Boxes suppress differences: for instance Locke, Berkeley, and Hume are standardly put into the box marked 'empiricism' yet this conceals points of wide, even vital, difference between them. Locke recognised a physical world of primary qualities; Berkeley denied it in any sense Locke would have acknowledged. Berkeley has to do double duty in the box marked 'idealism' as well as 'empiricism' yet there is no significant similarity between Berkeleian idealism which posits God, mind or spirits, and their ideas, and Platonic idealism posits a transcendent world of pure essences.