A Journey Beyond the Material: Exploring Federico Faggin’s “Irreducible”

https://www.philosophybasics.com/branch_idealism.html

Idealism is the metaphysical and epistemological doctrine that ideas or thoughts make up fundamental reality. Essentially, it is any philosophy which argues that the only thing actually knowable is consciousness (or the contents of consciousness), whereas we never can be sure that matter or anything in the outside world really exists. Thus, the only real things are mental entities, not physical things (which exist only in the sense that they are perceived).

Idealism is a form of Monism (as opposed to Dualism or Pluralism), and stands in direct contrast to other Monist beliefs such as Physicalism and Materialism (which hold that the only thing that can be truly proven to exist is physical matter). It is also contrasted with Realism (which holds that things have an absolute existence prior to, and independent of, our knowledge or perceptions).

[Laird]

There cannot be non-Monistic forms of Idealism, because that sort of doesn't make much sense

It depends on what the monistic target is: type or token. Idealism is necessarily monistic regarding type (of substance: there is only one, consciousness) but not necessarily regarding tokens (of consciousness: there might be truly only one consciousness as on Absolute Idealism or a plurality of consciousnesses).

When I differentiate between monistic and pluralistic idealism, I'm referring to tokens, i.e., whether there is truly only one singular Mind (consciousness) or whether there is a true plurality of minds (consciousnesses).

It depends on what the monistic target is: type or token. Idealism is necessarily monistic regarding type (of substance: there is only one, consciousness) but not necessarily regarding tokens (of consciousness: there might be truly only one consciousness as on Absolute Idealism or a plurality of consciousnesses).

When I differentiate between monistic and pluralistic idealism, I'm referring to tokens, i.e., whether there is truly only one singular Mind (consciousness) or whether there is a true plurality of minds (consciousnesses).

That's... not how it works in philosophical circles. A plurality of minds is still considered single, monistic substance ~ mind, no matter how many trillions or quadrillions or infinity.

In Idealism, there is no concept of "type" or "token" ~ that's a Physicalist / Materialist peculiarity.

Pluralism is about different base substances ~ matter, mind, astral, soul, spirit, etc, etc, depending on how you slice your definitions. But that becomes rather unwieldy because it has an interaction problem too ~ how do distinct substances interact without a common medium or nature?

Keep in mind that I am using the primary definition of "substance" here ~ a foundational entity of a metaphysics.