In primeval times (pre-flood) vicious and perverse angels came down and sinned with women and spawned a race of fierce and mighty men of old. I believe that this is where we get the myth of the demigods. Homer and Hesiod use the term, hemitheoi, meaning the person had one parent who was a 'god' and one who was a mortal. I personally believe that the secular/mythological cultural memory of these half-breeds, such as the mighty men of old mentioned in Genesis 6, were men like Hercules and Aeneas, and were the product of such matings. They really overstepped, and these particular unholy angels who did the deeds were locked up in Tartarus,