The LORD saw how great man's wickedness on the earth had become, and that every inclination of the thoughts of his heart was only evil all the time. (NIV)
John N. Oswalt
What the Hebrew says is that the very way we go about forming images in our minds is wholly corrupt... We do not automatically focus upon what is noble, good and true, as Paul urged us to do (Phil. 4:8). Rather our imaginations drift to the pornographic, the horrible, the perverse, and the corrupt.