Josef Fritzl, who repeatedly raped his daughter, justifies himself using the language of victimhood.

“The urge to have sex with Elisabeth was getting stronger and stronger. It was a vicious circle, a circle from which there was no exit — not only for Elisabeth but also for myself."

Fritzl thus equates his own "compulsion" with a massive steel door. Elisabeth literally had no exit. Fritzl's dungeon was merely in his head. Still, there is no excuse so absurd that some therapist won't believe it, and some defence lawyer use it. Cue Oedipus:

Fritzl also revealed that he had incestuous desires for his mother, Maria, since early childhood but managed to suppress them. His mother raised him on her own and had to take several jobs in order to support them in the years after the Second World War after she separated from her husband, who, according to Fritzl, “was a no-good scoundrel who was cheating on her".

Pots and kettles don't seem adequate. At least Fritzl Senior - we assume - was being unfaithful with women he hadn't fathered.

If Fritzl had fathered a child by his mother, what relation would that child be to the children he fathered by his daughter? Who knows, but somebody should give him a vasectomy. There is, as they say, a vas deferens between having children and not having children.