How about starting by being consistent at looking at history. When something was treated as a madness rather than a crime, there may have been a reason for it.
A society that can think of no better reason to do something than “law” is already lost.
Murder, even when committed through madness, is punished.
Yet, there’s no reason to think that abortion is “madness” rather than premeditated murder. A woman who gets an abortion knows what she is doing. It’s a pre-meditated act.