There is a social consensus on the desirability to protect private property, personal welfare, and current distributions. All individuals have freewill which they use to enter into a social contract with the state.
Laws represent a moral consensus.
All people are rational. All individuals are responsible for their actions and are equal. Punishment must be proportional to the interests violated by the crime. There should be as little law as possible, and implementation should be dictated by due process. Punishment should seek to reward useful activity and punish damaging activity.