Hi and welcome to the cesspool of egoism and agression which passes for a thread in these partsTheArtfulDodger wrote:
My problem with many Platonic-Kantians is that whilst I can agree that there is a distinction to be made between "appearance" and "reality", the distinction is by no means absolute nor exclusive. Put crudely, "appearance" is a subset of "reality", not a duality. Plato made the distinction an ontological duality, whilst Kant endorsed an epistemic dualism. Whilst I find these conclusions/metaphysics unsound, I certainly empathise with some of the basic premises. The problem lies not so much with the concepts these thinkers begin with, but, as you noted earlier, what they supposed these concepts (appearance, reality) implied.

I am interseted in this part of your post, because I agree that Kant made the (platonic) error of setting up the distinction between phenomena and neomena, defining all knowable by senses the 'phenomena' and all unknowable by senses the 'neomena' and thus brewing the duality which has poisoned western thought ever since. If we start with the neomena as the 'truth' and this is 'unknowable' we should not be suprised to conclude 'truth' is unknowable. This goes no where, its a simple circle back to the start point!
So, phenomena are the appearances, which constitute the our experience; noumena are the (presumed) things themselves, which constitute reality but cant be known.
Kant's conclusions that we can not know anything outside the phenomena is also his premise, and open to potential dismissal on this ground.
Kant supposed that the philosophical concept of material substance (reflected in the scientific assumption of an external world of material objects) is an a priori condition for our experience. This is now known to be an error, there is no bottom turtle to material substance, and open to potential dismissal on this ground
We know Kant's transcendental deduction of the categories as pure concepts of the understanding applicable a priori to every possible experience, we might naturally wish to ask the further question of him; whether these regulative principles are really true. Are there substances? To these further questions, Kant himself firmly refused to offer any answer.
Yet modern western thought plows ahead regardless, taking these as-if they were facts, resulting in threads like this as the culmination of thousands of years of thought!
(speculation warning! Looking at the big picture, applying the great hind-sight, maybe it was better that western thought believed truth unattainable so that science with its approximations and models could develop - it would possibly have never taken off in a metaphysical frame work where truth was attainable, but science could not claim to produce truth...)