  So much for question (i). What about question (ii)? The above discussion assumed that mens rea at the very least requires awareness. But criminal liability sometimes turns not on what D noticed, but on what \(D\) failed to notice—on circumstances that would have caused a reasonable person to refrain from doing what \(D\) did. It is where such circumstances exist that \(D\)’s actions are negligent. Some writers claim that negligence has no place in criminal law. If (C) is sound, and culpability requires awareness, then criminal liability should require recklessness at the very least. Others take a different view. They claim that when we are unaware of risks because of vices like arrogance or indifference, this makes us culpable for running those risks. So (C) is compatible with at least some instances of negligence liability in criminal law (Hart 1968, 136–157; Simester 2000, Alexander and Ferzan 2009, 69–85; Moore and Hurd 2011).