Analysis: Rape Is a Special Kind of Evil
The logic behind rape being qualitatively different from other crimes runs something like this.
We have created a hierarchy of evil, based on what does greater or lesser damages to the social contract but mitigated by necessity. Killing another human is the most destructive and in pretty much every society therefore punished the most harshly. But it is possible that killing another human being can be forgiven from need; self-defense or the defense of others. Even the violent suppression of a rebellion or the killing of an insolent underling by a leader can be construed as attempts to preserve the existing social contract.
People may steal to eat, torture others to obtain information which can save thousands, kill someone to preserve their own life. These are all actions which are normally punished if performed for their own sake, but which may be treated less harshly if performed "for the right reasons"; personal survival, the survival of another, or the survival of the group.
Constructing a situation in which rape becomes necessary for personal survival, the survival of another, or the survival of the group is extremely
difficult in modern society. It is in the top tier of the hierarchy of wrongs because of its ability to have permanent effects on the victim and those around the victim, along with torture and murder. That also means that any attempt to justify it instantly begs the question of why the use of the other two, particularly torture since both leave the victim alive, wasn't a relatively superior solution. Also unlike torture or murder, it has the possibility to actually create
an additional victim or victims of the crime.