From "Me And The Devil" by Nick Tosches.
The character is describing the evil thoughts we all have. The ones we keep to ourselves, the ones we never speak aloud. The really dark, vicious thoughts that only human beings could conjure up.
"So vile are they to us that we actually believe that they 'enter our minds' and we are unable to see that it was our minds that gave them birth. Our minds are not the random innocent victims of a breaking and entry by assailing demons in flight. Our minds are the wombs from which the demons seek the escape we disallow them."
Only a writer could describe this reality so exquisitely.