A law that is not consistently enforced does not serve its purpose.
Conclusion
To institute real law is not merely to declare that such and such behavior is forbidden; it is also to punish those who violate that edict. Furthermore, those who enforce law must punish without favor for their friends or malice for their enemies.
Rephrase: Instituting real law requires unbiased punishment of rule-breakers.
Evidence
A law that is not consistently enforced does not serve its purpose. Law without enforcement is not law; it is merely statute—a promise of law. To punish only those one dislikes while forgiving others is not to enforce law but to engage in the arbitrary and unjust exercise of power.
Evaluate
The passage clearly delineates what is necessary for instituting real law, making it both a statement of what should be avoided and a guidance on correct procedure. It tells us that enforcement needs to be unbiased, a crucial point emphasized towards the end. This fits a pattern where the argument builds up to a main idea by offering principles that lead to the conclusion, rather than starting with it or pivoting to it.
Goal
Find the best available meaning match for the idea that instituting real law requires unbiased punishment of rule-breakers.