I used to think about the punishment as the only way to reduce it, nonetheless, I started thinking about where the limit is, as humans, we're capable of immeasurable cruelty; considering that, deciding whether something is punishable, might quickly get us to extremism.
A book that gave me a whole new perspective about it was "Crimen y Castigo" (Crime and Punishment) by Michel Foucault.
I didn't check if that's the accurate name in English, I just translated from the Spanish one.