But prevention, by contrast, is when a person who has committed a crime and we have reason to believe would be likely to commit another crime, another offence—whether that's murder or something less than that—is prevented from committing a further crime because, at least for the time that that person is behind bars. Now, of course, the obvious rejoinder is, "Well, if a person is behind bars, they may merely be delaying their release into the community, at which point they'll continue to commit further crimes or they might learn further bad habits"—at the risk of using a trite phrase.