The ultimate achievement of wisdom
When Socrates professed ignorance at the Delphic oracle a mysterious voice proclaimed that he was “the wisest of men” and the timeless advice “Gnothi Seauton (know thyself)” was given to him. That indeed is the first achievement of knowledge. But, as Oscar Wilde believed, the ultimate achievement of wisdom is to recognise that the soul of man is unknowable.
I would say that the concept of soul and spirit has been the main of confusion in understanding the purpose of creation