On Legal Precedent

What is the Doctrine of Precedent?

In common law legal systemsprecedent is a principle or rule established in a previous legal case that is either binding on or persuasive for a court or other tribunal when deciding subsequent cases with similar issues or facts – Pattinson, Shaun D (2015-03-01).


Precedent involves an earlier decision being followed in a later case because both cases are the same. – Stanford Encyclopedia

Precedent is essentially a guideline which judges follow to make decisions about cases. For example, in Pennsylvania v Mimms, a new precedent was set in regards to cases involving traffic stops.

Essentially, a man was pulled over for operating a vehicle with an expired license plate. Upon being pulled over, the initiating officer identified a protruding object underneath the man’s jacket, which lead the officer to search the driver; as a result of said search, an unlicensed firearm was found on the driver. The driver was indicted with carrying a concealed weapon and possession of an unlicensed firearm.

The Pennsylvania court held:

The order to get out of the car, issued after the respondent was lawfully detained, was reasonable, and thus permissible under the Fourth Amendment…

As a result of said ruling, police officers are now able to, without violation of the 4th amendment, remove those who are detained from their vehicles. And any cases which are brought to a court that deal with this similar issue will be, according to stare decisis (The Doctrine of Precedent), approximately the same outcome.

The Features of Precedent

Precedent has a number of features that help shape the doctrine which it has become in modern law.

Horizontal and Vertical Precedent

Precedent has something known has verticality and horizontality. Vertical precedent refers to the obligation that lower courts have in following the decisions of higher courts, on both matters of fact and matters of law. Horizontal precedent refers to following a court’s earlier decisions even when that court is not above in the hierarchy; for example, when a court faces two separate cases that are similar, it will rely on the decision made in the first case to deal with the second case.

So, from superior-to-inferior (verticality), the precedent is binding. From equal-to-equal (horizontality), while within the same court, precedent is likewise binding; however, from equal-to-equal, while the courts are distinct states, the precedent can be persuasive, though nonetheless lacks binding.

Analogy and Similarity

Another key aspect to precedent has to do with similarity and analogy. Precedent involves analogy insofar as we appeal to similar circumstances between cases to then justify our reasoning. For example, in Adams v. New Jersey Steamboat Company (1896) 45 NE 369), an argument from analogy was made to establish that steam boats were more like inns rather than trains. The analogy was drawn: steamboats have lockable doors while trains do not, and thus they are more like inns; therefore, the steamboat owners have the same liability as inn owners for when something is stolen.

Something worth noticing, according to Frederick Schauer, within Adam v New Jersey, pertains the kind of reasoning used. Although Adam v New Jersey was indeed a precedent involving analogy, it was not a strict precedent; and in addition to that, the analogical reasoning used was rooted in similarities between objects rather than precedent to current case.

For starters, strict precedent entails that the court makes a decision irrespective of their own reasons and irrespective of whether they think the precedent to be good or bad; they simply follow what has been ruled before them. In essence, there is a constraint on their line of reasoning due to precedent. Therefore, Adam v New Jersey lacks strict precedent.

Moreover, the analogical reasoning used in Adam v New Jersey relates to the similarities between boats an inns when considering the issue of theft. Which means, because these two categories are alike in the fact that they both have lockable doors, we thus treat them as distinct from trains which have open compartments. And as a result, when determining whether the owner of the boat is under strict liability or not, we reason from the case of inns to boats.

In comparison to similarities between objects, we have another form of analogical reasoning: namely, case to case. Case to case reasoning is usually what people commonly mean when they speak of precedent; that is, the ruling on a previous case is used to determine a ruling in a subsequent case, if and only if the cases are similar enough. In such circumstances, the similarities can be between the matters of fact as well as the material evidence; so long as the cases are similar in enough respects, we can use analogical reasoning.

So, precedent relies on both similarity and analogy, and many confuse the two when attempting to reason about precedent.

What is The Difference Between Binding And Non-binding Precedent?

As implied in the above section, some precedents are strict and therefore binding, while other precedents are non-binding.

A binding precedent, irrespective of its persuasiveness, has to be followed by the court as matter of law. There are numerous instances of judges finding the substance of a precedent to be utterly unpersuasive but following said precedent, nevertheless.

Likewise, there are some precedents which are persuasive and have an influence on courts but are not binding. That is, in matters of horizontal precedent, one court can view, in cases of sufficient similarity, another courts ruling as persuasive. After which, the original court will rule in like fashion as the other court, even though the precedent is non-binding.

However, horizontal precedent is binding on a given court when a previous panel of judges belonging to that given court have decided a particular way in some specific case. These two types of horizontal precedent should not be conflated together.

Future Decisions and Precedent

As we now know, precedent, in some cases, entails that we follow precisely the same decision as beforehand; that is, when we rule x on case y, we likewise rule x on all other cases similar to y. But we have yet to discuss the consequences that come from doing so: what happens when we bind future decisions via our decisions made in previous circumstances?

As some argue, we get less favourable outcomes, while others argue we get more favourable outcomes; yet furthermore, we get less optimal but better on average outcomes, while still others argue we have just less optimal results.

For example, according to Frederick Schauer:

Accepting the constraints of precedent thus entails taking into account an array of instances broader than the one immediately before the decision maker. And this in turn means that although in no case can we make a decision that is better than optimal for that case taken in isolation, in some cases we will make decisions that are worse than optimal for that case taken in isolation. It thus becomes plain that adopting a strategy of reliance on precedent is inherently risk averse, in the sense of giving up the possibility of the optimal result in every case in exchange for diminishing the possibility of bad results in some number of cases. – Frederick Schauer.

Precedent A applied to 5 contexts; Precedent B applied to 5 contexts.

For Schauer, precedent is risk-adverse (which I take to mean preferable) on average since it will lead to less sub-optimal, as well as less optimal, decisions being made. However, though this is fine and well in a hypothetical world, I believe a more empirical measurement ought be adopted; only because I fail to see how Frederick’s conclusion amounts to a logical necessity about the world around us. And if his conclusion is not a logical necessity, then the actual matters of fact could be different.

For instance, when observing the matters of fact, we could find that precedent rulings are indeed optimal; that is, because these precedents are set by moderate judges, on average, we find in society that most believe the precedents to be reasonable.

Of course, that is only a thought experiment, and I have no intent to discuss whether most precedents are indeed reasonable or not; however, a point of caution should be taken. We cannot make hasty conclusions and justifications about the real world when our conclusions are in requirement of empirical evidence. Reality simply knows more than us.

Moreover, I also want to address the ambiguity of the term optimal. Such a term is value-laden and is thus difficult to define unbiasedly. For some, optimal can mean the outcomes which bear maximal utility, while it can mean, for others, the avoidance of disutility. So, it is not clear to me why we add the notion of “optimal” here, when it is, generally speaking, a relative term: the meaning varies person by person. It would be better, I believe, to state explicitly the metric used to measure the efficacy of legal precedent as opposed to couching our justifications in relative terms.

At any rate, many legal scholars believe precedent has something to say about future decisions, and so future decisions are a feature of precedent.

The Problem Of Relevant Similarity

It is one thing to observe that precedent is about the obligation of a legal decision maker to obey those decisions from above or before that constrain the decision maker in the instant case. It is another to determine which previous decisions actually have, or should have, this force. – Frederick Schauer

Essentially, the specifics of what makes a decision under consideration similar to a decision in a previous circumstance are in need of clarification and argumentation: they have to be identified and justified.

A good example of the necessity for clarification and argumentation is when a courts ruling brings about the possibility for consumers to sue manufacturers because of harm brought about by some specific defective product. Herein, which products are considered similar enough or do enough damage to constitute harm is unclear.

Let us suppose, for example, there are two automobiles which are manufactured by the same company; and let us furthermore suppose that one model was manufactured in 1950, while the other was manufactured in 2012. In addition, suppose both models brought about harm to the consumers.

In the 2012 model, suppose the courts ruled in favour of the consumers when the consumers brought a civil case against the manufacturing company. From that fact, we can perhaps now make an argument from similarity for the compensation of those who owned the 1950’s model. That is, the people who owned the 2012 model and were hurt by said model are similar to those who owned the 1950s model and were hurt by that model; the same company and the outcome of injury seem to make the matters of fact similar.

However, these outcomes of circumstance only appear similar on the surface of the matter. When we ask, “which specific defect lead to injury in 2012 that is similar to the defect that lead to injury in 1950,” numerous dissimilarities can be found. In example, a defect that arises from wear and tear will not be analogous to a defect that occurs within the first few weeks of owning the car. In addition, the harm which was brought about from the 2012 model can be far more detrimental to someone’s well-being than the harm brought about from the 1950 model, which thus makes them dissimilar.

Likewise, there are matters of law involved in establishing similarities. For instance, the statue of limitations can negate the possibility of some civil law suits; and so, in the case of the 1950 and 2012 model, we would have to see the matters of law that regard the degree of similarity, as the matters of law can make seemingly similar things dissimilar.

The point being, what constitutes similarity is contingent on numerous things. Sometimes motor vehicles are similar in the domains of law they are subject to, such as when Toyotas and Buicks are both similar for laws regarding breaks but are yet dissimilar when regarding laws about importation. And so, precedent is seldom obvious as we have to think carefully about purpose, category, and circumstances to determine similarity.

Why do we Follow The Doctrine of Precedent?

Why do we follow precedent in law? What are good reasons to believe in precedent? Well, there are a few.

The reasons we believe in precedent are:

  1. Fairness
  2. Predictability
  3. Efficiency

Precedent is Fair

One of the advantages of precedent is that our decisions will apply equally to like cases; meaning, we will treat like cases alike. And the opposite of treating like cases alike will lead to unfairness. Lets see why.

The word “unfair” pertains to human constructed systems; that is, gravity cannot be unfair as it applies the same rule to everyone, equally; however, humans can be unfair when they apply a given rule in radically different ways for precisely the same matters of fact. It is unfair for a judge to allow one person to steal while simultaneously jailing another person for stealing, especially if the thing stolen in each case is similar. (See Article: “Is Life Fair?“).

But when we have a binding precedent, like cases are treated alike. We avoid the unfairness of applying rules in an arbitrary fashion.

Precedent is Predictable, Reliable, and Stable

Another justification for precedent has to do with the predictability, stability, and reliability.

Precedent allows for the business, civilians, and lawyers to understand the law and how it will function; upon which they can then make their decisions. For example, if we return to the inn and steamboat scenario, owners of steamboats would need to know which kind of liability they are under to inform their decisions. If they cannot grasp how liability is ruled on, then they cannot reasonably know the duties which they have to their customers and general public.

And with predictability comes stability. The stability of precedent allows for businesses to maintain operations in a specific way for a prolonged period of time; they will not have to scramble every other month to reassess their logistics and business models.

So, precedent can be preferable for the greater society around, as it brings norms to the legal system.

Precedent is Efficient

Courts are given many cases each day, they are often very busy and overworked. And that means, judges have to rule on numerous cases each month. And given the limited amount of time a judge has, it makes sense that they would treat like cases alike rather than rejudge them.

If a judge had to rethink each and every case, the legal system would become woefully inefficient; judges would have to spend extra time and effort on something which has already been dealt with. This is analogous to a mathematician being forced to re-solve each and every problem that has been solved before them.

By having a precedent, we can make the decision making process more efficient than it would otherwise be. Judges will spend less time on repeat/common violations. And that will lead to both more cases being heard and tougher cases getting more attention. Precedent makes for more efficient judges.

Critiques Of Precedent

There are, to no surprise, quite a few critiques of precedent. To name a few critiques of precedent, we have:

  1. Collective Irrationality
  2. Originalism and the Constitution

Collective Irrationality

One critique of precedent, in the context of appellate decisions, is collective irrationality. According to Stephen Gageler and Brendan Lim:

Appellate adjudication is committed to decision-making by groups and it is committed to decision-making by adherence to precedent. Those commitments are in tension. Group decision-making is inherently susceptible to collective irrationality in the form of internal inconsistency. This presents particular problems for achieving consistency through precedent-based decision-making. –  Gageler and Lim

The problem of collective irrationality arises because group decisions are derived by aggregating individual opinions, which lead to inconsistencies, while precedent is designed to remain as consistent as possible: consistent inconsistencies.

So, there are instances where a collective judgement can set an irrational precedent that then plagues legal decision-making. Consider the following example:

Screen Shot 2019-05-20 at 11.56.49 AM
The defendant not being liable is an irrational conclusion.

The summation of the judgements leads to something incredibly irrational; namely, that a person who both formed and breached a contract is not liable.

Original Meaning of the Constitution and Precedent

Some authors believe precedent ruins the original meaning of the constitution. In the one hand, we should follow precedent if we are to treat like cases alike as well maintain the binding nature of precedent; yet, in the other hand, if there is some precedent which goes against the original meaning of the constitution, then precedent and the constitution are at odds.

So, the critique of precedent from original meaning theorists pertains to the unconstitutionality of following precedent which is informed by an unconstitutional decision.



Ideasinhat is a business development analyst and longtime reader of academic literature. He writes books and essays on science and philosophy, and posts them to this website. The essays, as with the books, cover topics from psychology, philosophy, and cognitive science to economics, politics, and law.

Leave a Reply