Which is more morally or socially important? The rule of law or true justice in each and every case.
Laws are going to be unjust in edge cases - hence very limited "strict liability" and, until recently, it only applying to minor offences. And the right to trial by a jury of your peers, also now diminished. However the lack of law, or the lack of any attempt to enforce a body of laws, is likely to lead to manifest injustice in many more cases.