Legal Reasoning: Criteria and Forms

Legal Reasoning: Criteria and FormsLegal reasoning deals with the steps and the inferences made by judges, lawyers, and legal researchers in reaching a conclusion over the state of the law on some issue.’ Legal reasoning is followed in most legal research activities. The relationship between law and reasoning is intuitive and universally acknowledged. Because the law is frequently narrated in an open-textured way, it provides scope for multiple interpretations and analysis, and judicial decisions are often reached through practical argumentation.

Judges and lawyers apply legal reasoning in one form or another in their day-to-day affairs in providing solutions to immediate problems. In addressing ‘legal reasoning,’ we have first to define the expression ‘reasoning.’ The expression ‘reasoning’ is used to mean the process of guiding, deciding, on a given course of action’ and a decision-making process.

Thus, the expression ‘legal reasoning’ can refer to the following three situations;

  1. reasoning to establish the existing content of the law on a given issue,
  2. reasoning from the existing content of the law to the decision which a court should reach in a case involving that issue which comes before it, and
  3. reasoning about the decision which a court should reach in a case, all things considered.”

In essence, legal reasoning can be defined as reasoning used for explaining, guiding, interpreting, evaluating laws, legal principles, and norms. Thus, knowledge of the law and the facts of a case are a prerequisite of legal reasoning.’

‘Legal reasoning’ is used in both broad and narrow sense. In the broad sense, it refers to the psychological processes by which judges reach decisions in those before them. Such processes are comprised of ideas, beliefs, conjectures, feelings, and emotions. In the narrow sense, legal reasoning is concerned with a judge’s decision on questions of law.

In the narrow sense of the term, ‘legal reasoning’ refers to the arguments that judges give in support of the decisions they render. These arguments consist of the reasons for the decisions, and these reasons are intended as justifications for the decisions.

Legal reasoning is concerned with how different considerations contribute to the determination of the law. Thus, legal reasoning can be shaped by both legal and non-legal considerations. While legal considerations can include rules found in statutes, precedent, dicta, and legal principles, non-legal considerations encompass moral values, practical constraints, or consequential effects.

Legal reasoning is usually applied in three areas;

  1. judicial decision-making,
  2. argumentation in jurisprudence and
  3. law-making.

Thus, legal reasoning is applied to applying the law in jurisprudential argumentation and creation of law.

However, legal reasoning is predominantly associated with judicial application and interpretation of the law. Thus, legal reasoning in the common law system places considerable weight on arguments about the consequences of applying legal rules and of judicial decisions.

There are three categories of consequences: first, legal consequences, which refer to the effects of a given rule on the body of the law; secondly, logical consequences, which refer to the result of the logical development of the rule; and thirdly, the behavioral consequences, which refer to the effect of the rule on how people actually behave in society.

Legal reasoning is different from other kinds of reasoning. For example, it differs from moral reasoning in many ways. However, moral content is a universal requirement of legal reasoning. Legal reasoning also differs from scientific reasoning.

While scientific reasoning is concerned about discovering the truth, legal reasoning deals with normative statements, which are based essentially upon a values judgment made by the legislature or a judge that a particular consequence should or ought to follow certain behavior.

The contour of legal reasoning can be shaped by both formal legal rules and extra-legal considerations. Formal legal rules are the main guiding factors for legal reasoning. But the contour of legal reasoning is not solely determined by legal arguments. Extra-legal considerations like principles of justice, morality, the social policy may be applied in legal decision-making.

Thus, a strictly legalistic approach to legal reasoning may not achieve the desired social goals that are intended. The jurists had long refuted the purely legalistic approach in legal reasoning.

Indeed, the contours of legal reasoning are profoundly shaped by “the felt necessities of the time, the prevalent moral and political theories, and intuitions of public policy, avowed or unconscious, even the prejudices which judges share with their fellow-men.”

Objectives of Legal Reasoning

As mentioned earlier, legal reasoning is primarily meant for judicial decisions. Therefore, a judicial decision must be principled in the sense that it can be justified only by an appeal to a general rule or principle, the applicability of which transcends the case at hand.

By offering legal reasoning, judges justify their decisions to the interested public, including the parties to the case, all other people who may be immediately affected by the decision, the legal profession, and the community.10 Legal reasoning in the proper sense denotes a belief in objectivity in finding answers to questions of law that judges can arrive at decisions through applying principles.

Thus, legal reasoning always requires principled justifications.11 Justification, according to John Rawls, “seeks to convince others or ourselves, of the reasonableness of the principles upon which our claims and judgments are founded.”

Justification implies that the same rules of logic should discipline good legal reasoning. Therefore, logical soundness is one of the important aspects of legal reasoning.

Some writers argue that persuasion rather than justification is the objective of legal reasoning. Chaim Perelman is the main proponent of this view. According to him, the decision which is rendered authoritative necessarily entails argumentation which is to be evaluated by the persuasiveness of the reasons given for the decision.

He observes that argumentation, which is the ultimate method of legal reasoning, necessarily employs reasons which are tested by their effect in persuading those whom it addresses. Thus, for Perelman, legal reasoning is a practical argumentation that aims to persuade rather than establish the truth.

However, there is a predominant view that just as an objective of legal reasoning is more convincing and more acceptable than persuasion.

Criteria of Legal Reasoning

Since the purpose of legal reasoning involves the justification of a legal decision, it must conform to certain criteria and relevant legal norms.

The following are the criteria that judges must observe in legal reasoning:

Objectivity and Reasonableness

Legal reasoning in judicial decisions must be based on objective standards and reasonable moral judgment and must testify to a standard of rational justification. In fact, ‘moral requirements’ are considered as one of the major criteria of good reasoning.

The requirement of moral reasonableness as the criteria of good reasoning implies the following issues, and firstly, a judge must carefully study the case before him, consider the precedents, statutes, and legal principles which have been cited to him, and must be attentive to all the facts of the case which may have legal significance.

Secondly, a judge must be impartial in the sense that his personal interest or bias must not influence his decision. It also implies that a judge is supposed to disqualify himself from sitting in a case where his personal interests are involved. In deciding cases, he must not give special weight to the interests of his own socio-economic or professional class or his own racial or religious group, and so on.

Third, he must render reasons for his decisions.

Thus, to avoid arbitrariness in their decisions, judges should articulate the reasons for their decisions to justify them. Thus, a reasoned decision also ensures the justifiability of a decision. Here justification is concerned with the normative aspect of a decision and the truths of logic in tracing the correctness between the conclusion and premises of arguments.’

Reasoned decisions serve as guidance to other individuals on what the law is and on how their cases are likely to be decided in similar cases. In this way, individuals can adjust their future conduct.18 Reasoned decision is integral to the sound adjudication and rationality of the legal process.


The judges should be consistent in legal reasoning in the sense that he applies the same reasons that he gives in one case to the deciding of another case which involves a similar set of facts or whri>h raises similar legal issues.’

The requirement of consistency figures prominently in the discourse of precedent, which involves judges’ development by deciding particular cases, with each decision being shown to be consistent with an earlier decision by a court. The central idea of precedent derives from a basic notion of justice that, like cases, should be treated alike. Thus, principled consistency is the basic rule governing the common law principle of precedent.


Coherence plays an important role in providing integrity in legal reasoning and guiding judges seeking to interpret the law correctly.’ Coherence is not mere logical consistency in the decisions. Rather, it is treated as integrity in legal interpretation. It also means that in good legal reasoning, the judge tries to consider all the relevant factors in an appropriately dispassionate way. As a result of this consideration and reflection, the judge can arrive at a coherent decision.

Coherence has been explicated by MacCormick in terms of the unity of principle in a legal system, contending that the coherence of a set of legal norms consists in their being related either in virtue of being the realization of some common value or values or in virtue of fulfilling some common principle or principles.

In his famous book Legal Reasoning and Legal Theory, MacCormick proposes a model of legal reasoning in which it is a necessary condition for a judicial decision to be justified that it has “value coherence” with existing laws. Value coherence depends on the application of ‘principles.’ Principles state some value or policy that guides reasoning. MacCormick recognizes that coherence can be a virtue of an entire legal system.

He observes:

“…in arguing from coherence, we are arguing for ways of making the legal system as nearly as possible a rationally structured whole which does not oblige us to pursue mutually inconsistent general objectives.”

Different Forms of Legal Reasoning

There are two main forms of legal reasoning as reasoning by analogy: inductive reasoning and deductive reasoning. However, judges seldom use these technical vocabularies in their decisions.

Legal Reasoning by Analogy

Analogical reasoning refers to noting similarities between cases and adapting them to fit new situations. Argument by analogy is common both to judicial decisions and statutory interpretation. But analogical reasoning is frequently used by judges and lawyers in arguing that previous decisions are or are not sufficiently similar to be relevant to the issue in question.24 In other words, analogical reasoning demands that similar cases should be treated equally.

The important significance of analogical reasoning lies in the fact that it introduces a degree of stability and predictability in interpreting the law. As a result, analogical reasoning can develop new laws and learn commentary about the law. In this way, it can initiate legal reform.

The leading authority on analogical reasoning is Edward Levi, an American jurist who, in his famous book, “An Introduction to Legal Reasoning,” described the process of analogical reasoning in the following way:

The basic part of legal reasoning is reasoning by example. It is reasoning from case to case. It is a three-step process described by the doctrine of precedent m which a proposition descriptive of the first case is made into the rule of law and then applied to a next similar situation. The steps are these, the similarity is seen between cases; next, the rule of law inherent in the first case is announced; then, the rule of law is made applicable to the second case.

The finding of similarity or difference is the key step in the legal process. The determination of similarity or difference is the function of each judge. The legal process is not applying known rules to diverse facts But is a system of rules discovered in determining similarity or difference.

The main proposition of Levi’s treatment of legal reasoning is that the determination of analogies is a crucial element in such reasoning.

Legal reasoning is frequently concerned with whether the case presently before a court is relevant like other previously decided cases. However, Levi emphasizes that general principles typically do not play a decisive role in answering such questions. Instead, an analogy can guide the application of rules in such situations.

Every legal system employs analogical reasoning in one form or another to justify judicial decisions.

For instance, in civil law or continental systems, analogical reasoning is used as a tool to fill a gap in legislation or code. In the civil or continental legal system, the basic concept of analogical reasoning derives from the fact that codes are enacted to supply guidance on any legal question in law encompassed by the code. Still, it is assumed that legislature inevitably leaves some gaps in a code.

Analogical reasoning can be used as a tool to fill such a gap. Thus, it is mainly used as a tool of interpretation of a code.

Analogical reasoning is one of the fundamental principles of common law. In the common law system, the most common form of analogical reasoning is precedent, by which court decisions are recognized as a valid source of law. In precedent, judges must decide the cases before them according to existing precedents in the domain.

It means that when a previously decided case discovers a new rule, it governs the similar cases to be decided. Thus, the legal basis of the precedent derives from the fact that it was decided based on legal rules and standards, which justifies applying a particular precedent. Precedent is thus a matter» of applying prescribed legal rules and standards.

As a result, conclusions drawn by inference from analogy by applying precedent are not causal but the similarities referred to in the legal argument support a normative inference about the correct legal outcome.

Precedent plays an important role in promoting certainty in the judicial process and predictability in the law. In the words of Roscoe Pound:

The chief cause of the success of our common law doctrine of precedent as a form of law is that it combines certainty and power of growth as no other doctrine has been able to do so. Certainty is insured within reasonable limits in that court proceeds by the analogy of rules and doctrines in the traditional system. It develops a principle for the cause before it according to known techniques.

Growth is ensured in that the limits of the principle are not fixed authoritatively once for all but are discovered gradually by the process of inclusion and exclusion as cases arise, which bring out its practical workings and prove how far it may be made to do justice in its actual operation.

Analogical reasoning does not necessarily mean that such a previous case needs to be precisely on point with the case to be decided. In other words, analogical reasoning must satisfy the requirement of formal justice that like cases should be treated alike, but it does not mean that two cases should be identical.”

In such cases, the court must decide whether the previous case is sufficiently analogous for its rule to govern the new case to be decided. It may also happen that there is more than one case that arguably applies to the case at hand. In that circumstance, courts must determine which of the previous cases is most similar to the case to be decided.

While analogical reasoning is closely associated with the invocation of precedent, courts also invoke it to interpret statutes.

For instance, a new statute or provision may be interpreted in the light of the statute that it replaces. In interpreting the law, a judge or commentator may draw analogies between the two pieces of legislation to derive similarity in an outcome that the statutes seek or similarity in policy considerations underlying their adoption.

The reasoning by analogy also closely resembles the “inductive reasoning.” In general, the process of inductive reasoning involves making several observations and then proceeding to formulate a principle that will be of general application.

Inductive reasoning starts with observations of the facts and arrives at a general conclusion. Thus, induction reasoning follows two processes: observation and generalization. Thus, inductive reasoning is a process of reasoning by example. However, inductive reasoning cannot be conclusive. Inductive reasoning is not about proof, but it is purely about justification.

Inductive reasoning fundamentally differs from the deductive form of reasoning. The difference between induction and deduction is primarily the difference between justifying for and proof of an outcome. According to one author,

The difference between deductive and inductive reasoning is that deductive reasoning is a closed system of reasoning, from the general to the general or the particular. The premises tend to support the conclusions in an inductive argument, but they do not compel the conclusion. Judges are involved in a type of inductive reasoning called reasoning by analogy. This is a process of reasoning by comparing examples.

Thus, induction is closely related to analogical reasoning because both rely on prior experience and interpretation. In inductive reasoning, lawyers and judges find a general proposition of law by surveying relevant statutes and case laws.

Deductive Reasoning

The legal argument also relies on deductive reasoning. Deductive reasoning usually involves applying a general rule, which may derive from a particular statute or case and apply to a particular case and then draw a conclusion.

In deductive reasoning, a logical conclusion is drawn from the major premise and minor premise. The process of deductive reasoning involves stating one or more propositions, and then a conclusion is reached by applying established principles of logic.

Deductive reasoning is only applicable once a clear major premise has been established. According to a learned commentator, deductive reasoning is of limited use in legal reasoning. This form of reasoning leaves no space for examining the truth or otherwise of the premises.

Deductive arguments only hold factual propositions, not of norms. Deductive legal reasoning establishes a formal logic through identifying or adopting basic premises from which determinate legal conclusions can be deduced. Deductive reasoning is an important element of legal reasoning as lawyers are often called upon to decide how a principle of law applies to a given case.

However, even pure deductive reasoning can justify a judicial decision if the major premise is an established rule of the legal system; the minor premise consists of proven facts. Then the conclusion arrived must be true and can be normatively justified.


Legal reasoning is frequently found in the interpretation and application of law or legal norms in a particular case. An acceptable form of legal reasoning must fulfill the requirements of both formal legal rules and moral considerations. The legal reasoning must also be persuasive, consistent, and coherent to make a decision rationally constructed and integrated. Thus, the integrity of legal principles is central to a coherent set of legal reasoning.

Among the various forms of legal reasoning, the analogy is the most commonly used one applied in judicial decisions and statutory interpretation.

Analogy plays a great role in legal reasoning to make the decision coherent and consistent. In this way, analogical reasoning promotes legal certainty and predictability in judicial decisions. The process of analogical reasoning involves the determination of likeness between the previous case and the case at hand and the determination of ratio decidendi of the previous case and its application to the case at hand.

On the other hand, deductive reasoning is relevant only in clearly established statutory rules or case law, rules, and principles.

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