Why do fathers sexually abuse their daughters?

He was so very, very sick. This is not an excuse...it is a fact. For whatever reason, he chose not to get help. His denial of the incidents proves his guilt. He denies it because he knows it is wrong. Part of his sickness, some sort of narcisistic thought process, allows him to believe that he is above everyone, and everything. He thinks the world revolves around him, and therefore, he should have what he wants, and pay no consequence for. They do know what they are doing will destroy their child, and do it anyway. This is part of the narcisistic mentallity...he believes he comes first. There are alot of other mental sicknesses he is/was dealing with. It would take a mental health professional to deal with them all. I am not a professional, but I am an abused child myself. I have learned this from years and years of therapy, and the many books I have read. My father died still saying it was all my fault, I was 3 years old when it began. I still don't have all of the answers, and may never. I just keep trying and trying. I truly feel for you and will pray for you. Take care and know that it is not your fault.