Menschen v. Serravo (1992) depended on the distinction. : 554-559 in People v. Serravo, the court held that the standard of knowledge of moral injustice in the M`Naghten rule is the objective standard. The court wrote: « Moral injustice can be interpreted either by a purely personal and subjective norm or morality, or by a social and presumably more objective norm. We believe that the more reasoned interpretation of the word « evil » in the phrase « unable to distinguish right from wrong » refers to an illegal act measured by social moral norms. What cannot be formulated in an objective law cannot be legislated – neither in a free country, nor if we want to have « a government of laws and not of men. » An indefinable law is not a law, but only a license for some people to govern others. In U.S. criminal law, subjective and objective norms are legal norms relating to a defendant`s knowledge or beliefs in a criminal case.  : 554 to 559  An objective measure of reasonableness requires the investigator to consider the circumstances from the perspective of a hypothetical reasonable person, without the unique specific physical and psychological characteristics of the accused. A subjective measure of reasonableness is whether the circumstances would give rise to an honest and reasonable belief in a person who possesses the particular mental and physical characteristics of the accused, such as personal knowledge and personal history, if the same circumstances could not produce the same in a generally reasonable person.  Objective laws define the general principles that judges then apply in specific cases. For example, Rand explains, custody laws need to be clearly defined to prevent a judge from arbitrarily removing a child from his or her parents.
In the context of those principles, however, the court may have a margin of appreciation, provided that it is clearly limited and defined. For example, she says, the law should determine not only the factors to be considered in determining the best interests of the child — factors such as the moral character of parents and the financial support they can provide — but also the types of evidence judges will use to judge morality. The use of force requires objective rules of evidence to establish that a crime was committed and to prove who committed it, as well as objective rules to establish penalties and procedures for execution. The men who try to prosecute crimes without such rules are a mob of lynch mobs. If a society left retaliation in the hands of individual citizens, it would degenerate into a mob law, lynching, and an endless series of bloody private feuds or quarrels. An objective law protects the freedom of a country; Only a non-objective law can give a statist the chance he seeks: a chance to impose his arbitrary will—his policies, decisions, interpretations, application, punishment, or favor—on unarmed and defenseless victims. When people are trapped in the trap of non-objective law, when their work, their future and their livelihood are at the mercy of a bureaucrat, when they have no way of knowing what unknown « influence » will act against them, for what unspecified offense, fear becomes their fundamental motive, if they stay in the industry – and compromise, Conformity, obsolescence, dullness, the dark gray of the middle of the road are all that can be expected from them. Independent thought does not submit to bureaucratic edicts, originality does not follow « public policy », integrity does not apply to a license, heroism is not fostered by fear, creative genius is not evoked with a weapon. Rand also discusses the dangers of non-objective law, i.e. « a law without a specific definition, which can have as many different interpretations as there are people.
According to a non-objective law, a citizen cannot say what is allowed or prohibited. These laws include preventive law (« You are not keeping the entire population, including the best of your citizens, at the level at which only the worst engage ») and antitrust law.