Plato’s Idealism:
“If we are ever to have pure knowledge of anything we must get rid of the body and contemplate things by themselves with the soul by itself … no pure knowledge is possible in the company of the body … so long as we are alive, we shall continue closest to knowledge if we avoid as much as we can all contact and association with the body … and instead of allowing ourselves to become infected with its nature, purify ourselves from it until God himself gives us deliverance.” (Phaedo 66e)
My full lecture on Idealist themes of supra-naturalism, higher knowledge, mind-body duality, ascetic/sacrifice ethics, Plato’s Myth of the Cave and Kant’s writings on education: