Analogies, such as precedents, appear in a doctrinal context. This case raises a legal question, for example is imitation of a friend the consent of the victim in rape law, is burning crosses a protected “speech” in the First Amendment of the United States Constitution, does the defense of coercion require that the defendant have acted as a reasonable person would have done? Other cases concerning the validity of consent or the scope of protected “speech” or the adequacy of the defence offer potential analogies. An analogy may be either to another case or to another legal doctrine, and the analogy is based on the fact that, in both cases, there is a common characterization of the facts or both doctrines relevant to the question. Thus, knives can be analogous to weapons if the problem affects weapons, but knives can also be analogous to teaspoons if the problem is with cutlery. Coercion may be analogous to provocation when it comes to defences, but coercion may also be analogous to incitement to complicity. Two doctrines or series of facts are not analogous in the abstract, but in the context of a legal question.  Two questions arise for the analogous argument. First, by what process does a decision-maker identify the “common characterization” between the present case and the analogous case? Second, what kind of justification does the common characterization offer? As regards the first question, just as no two cases are identical in all respects, two cases are not such that a common characterization of the facts cannot be found. But not all cases are supposed to provide an analogy, so what restricts or directs the choice of analogies? The answer to this question is found in the question of the justification of analogies. What is the reason for an analogy to decide the present case in the same way? This last point refers to the fact that cases are rarely justified on the basis of principles alone: instead, there are a number of considerations that are applicable and justify the result. A principle can be applied with equal force to two cases with very different facts, but these differences cannot make the cases very analogous. This suggests that while principles provide arguments for achieving a particular result, they do not explain the nature of analog thinking.
Another line of criticism is that courts often do not articulate their use of analogies in the sense of a “principle” inherent in a previous case. Where principles are used as arguments for an outcome, earlier cases are cited as examples of the application of the principle rather than as analogies with the facts of the present case. If another case is cited as an analogy, the focus will be on the extent to which the analogy is “narrow”, i.e. on the specificity of the common characterization of the facts of the two cases and how that characterization relates to the reasons for the earlier decision. The more specific an analogy is, the stronger it is; The more abstract the characterization, the weaker the argument as an analogy. The reason for this is that the more specific the analogy, the less room there is to distinguish the two cases, while the more abstract the analogy, the more reasons there are why the two cases can be considered significantly different. So, while it is legal to consent to tattooing, it is also legal to consent to a decorative brand image that is closely analogous.  On the other hand, the analogy between boxing and sadomasochistic activities is even more distant, although both involve the deliberate infliction of a certain level of damage.  At the analogous hearing of actions, it is desirable that the court separately record the evidence relating to different actions/cases and render judgments separately. Evidence in one prosecution or case is not evidence in other prosecutions or cases.
Similar reasoning helps to make the outcome of cases more predictable by giving weight to existing legal decisions and doctrines. However, this only happens in a certain context, where, despite the fact that policymakers do not share a unified normative vision, there is a high degree of agreement on the existence and meaning of certain values. A certain degree of agreement is necessary for decision-makers to consider a case as analogous, as it is based on what they consider to be the correct justification for the previous decision.