Whenever the mightly eagle came to prey on poor Prometheus, the eagle chose his liver to feed upon. I have always thought Why liver? Now I realized, that the liver is the most suitable organ for repeated damage: it is the fastest growing organ in the human body! (that’s why during liver transplantations they don’t need whole liver from the donor, only ~1/3) Given that and his Titan origin, Prometheus must have endured the feast for a long long time. So it may seem that Old Greeks knew more about human anatomy than we thought. How could they possibly know about the regenerative abilities of the liver? I have to a little research in the following winter nights.