As for the first point, ordinary lawyers generally think that precedents constitute the law until they are crushed. Once repealed, the subsequent decision (usually) takes effect retroactively, so the law is amended for the past and the future. But when a case is distinguished, it is not often assumed that the law was one thing until the subsequent decision of a court, and now another thing. The law is already considered to be the subject of various distinctions before the subsequent decision, which were not mentioned by the previous court. In fact, part of the ability of a good joint lawyer is to understand the law as it was not stated by the previous court: learning that cases are “distinguishable” is an integral part of general legal education, and no ordinary lawyer would be competent not to recognize that the law should not simply be identified by the ratio of a previous decision. Ordinary lawyers therefore do not conceive of a distinction analogous to crushing. There are two questions about analog thinking. 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? 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. It also means that, although they do not agree in different cases on the solution found in different cases, it is unlikely that the disagreement will be deep, but it will be reasonable. (For an argument that this requirement may be overstated, see Sunstein 1993, 769-73). A final justification for the doctrine of precedent is that it is desirable to give the courts the power to legislate. The idea here is that it is useful for the courts to have the power to improve and supplement the law (Hart 1994, 135-6; Raz 1979, 194-201). The assumption behind this justification is that the law is sometimes incomplete and requires greater precision, or that it is imperfect and needs to be corrected. From this point of view, the courts are analogous to delegated legislators: they have limited powers to legislate within a broader framework of doctrine.

The reason-based approach of analog reasoning focuses on the justifications for the analogous case (for two very different reports, see Raz 1979, 201-6, and Brewer 1996). It examines to what extent the statement of reasons for the decision given in the previous case is applicable to the present case. Take the case of the imitation of a friend in rape law. Whether this situation is analogous to the imitation of a husband depends on the reasons for his erroneous consent. There doesn`t have to be a single principle underlying the justification: it can be based on a number of factors that reinforce the conclusion. It is widely accepted that the existence of an analogy ultimately depends on the reasoning of the analogous decision. The facts in a case may be outside the relationship of an existing precedent, and therefore the court is not bound by the precedent. On the other hand, the justification for the earlier decision may apply to the subsequent case and thus provide a similar argument.

Take the case of the imitation of a friend in rape law. Suppose there is authority to declare that a husband`s identity theft interferes with consent for rape purposes. Whether the imitation of a friend is analogous depends on why such a conjugal imitation interferes with consent. If it is assumed that part of the meaning of marriage is to share physical intimacy with that particular person, then the justification is applicable to other close personal relationships. If, on the contrary, the reasoning is that consent to an imitator involves committing adultery, that is, an action that is different in its nature from the action that has been agreed, then the analogy, although the two situations are obviously very similar, will fail. 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.