Are you suggesting that our senses do not tell us about things in as themselves? What would we know of intelligible forms or an external world.
"philosophers have discussed this same shit for thousands of years."
Really? You give assertions that philosophy does not progress and build upon earlier work. It could be said that all of Philosophy is a work of ethics. I will agree that philosophy hitherto the Renaissance was nothing but foot notes on Plato.
Descartes did a good job dismissing early moral skepticism, but skepticism is can come about from many other areas of philosophy. Nihilism is an existential form of skepticism and we have logical skepticism in every form of logic.
"If you can read and actually comprehend" (a pretentious statement I might add) Kant, you would see that he tears apart reason and suggests an external world. Moore gives a proof of an external world, 'here is one hand, here is another hand'. We can also look at his logic which accounts for the 'Moore shift.
Where S is a subject, sp is a skeptical possibility, such as the brain in a vat hypothesis, and q is a knowledge claim about the world:
Common Skeptical Argument
S doesn't know that not-sp, then S doesn't know that q
S doesn't know that not-sp
Therefore, S doesn't know that q
Moore's Logic
If S doesn't know that not-sp, then S doesn't know that q
S knows that q
Therefore, S knows that not-sp
Skepticism has it's place.
I have made large jumps in my arguments, but if you wish to see a long drawn out proof I would love to. I have made large leaps through philosophical eras to prove that OP does not know if he is retarded or not.