No - 'rayiner gave the example of punishing someone who killed their abusive spouse. First, the actual punishment certainly doesn't deter them from committing t

No - 'rayiner gave the example of punishing someone who killed their abusive spouse. First, the actual punishment certainly doesn't deter them from committing the same crime again in the future (they are, statistically at least, not particularly likely to marry another abusive spouse). Second, the threat of future punishment is almost certainly insufficient to dissuade them from the original act: if they feel like they're in immediate physical danger, they probably are reasoning that it would be worth it for them to risk punishment. Besides desperation, there's also passion and mental instability. There's enough cases where you might just not be thinking about the potential punishment at all when committing a crime, meaning it doesn't deter you. For mental instability, we as a society have mostly decided we're okay with reducing/eliminating punishment (and perhaps that you should be institutionalized instead); for passion we generally haven't decided that, except perhaps with the concept of "temporary insanity."