Fundamentals

Rule of Law: What It Is and How It Limits Power

By Daniel Sardá · Published on September 14, 2026

8 min read1,615 words

The rule of law subjects those who govern to public, general, and reviewable rules. Its safeguards make that restraint enforceable.

An authority may point to a law and still act arbitrarily. Consider an office that denies a permit using criteria nobody can know, applies a new requirement to events that have already occurred, or grants the same application to some people while denying it to others without explanation. The mere existence of a legal text does not settle the matter: what matters is whether that text truly constrains the person making the decision.

The rule of law is an institutional order in which public authorities are subject to known rules and legal limits, and their decisions can be examined by independent and impartial courts. It does not simply refer to the state, nor does it mean obeying any law whatsoever. It is a way of making sure that public coercion does not depend on the shifting will of one person or a temporary majority.

From a classical liberal perspective, that is its central value: it protects a sphere of freedom by requiring power to be exercised under general, public, and controllable rules. It does not guarantee that every policy will be wise or every outcome just. It does create conditions for demanding reasons, challenging abuses, and knowing in advance what an authority may do.

Key idea: Having laws describes a legal system; having the rule of law means that those who govern are also subject to rules and effective checks.

When power no longer depends on whim

The European Commission places legal limits on public authorities and judicial oversight at the starting point of its definition. The United Nations adds decisive elements: laws must be public, applied equally, adjudicated independently, and capable of binding the state itself. There is no single closed doctrinal list, but these references help identify the concept’s common core.

The practical question is predictability. Someone opening a business, filing an application, or contesting a penalty needs to be able to know the relevant rules and reasonably anticipate how they will be applied. This does not mean rules can never change. Societies may reform them. It means that change should not work as an ambush or leave citizens at the mercy of hidden instructions or personal exceptions.

That is why the rule of law is related to a government of laws, but is not exhausted by a solemn phrase. A written rule that grants unbounded discretion, permits no review, or is applied selectively retains the appearance of legality while weakening the protection law should provide.

Safeguards work as a system

It is tempting to present the subject as an inventory of principles. It is more useful to see what each safeguard contributes and what happens when it is absent. The Venice Commission includes, among other criteria, legality, legal certainty, prevention of abuse of power, equality, and access to justice. The European Commission also emphasizes the separation of powers and effective judicial protection. Each component addresses a different vulnerability.

Public, general, and predictable rules

Legality requires public action to have a legal basis; legal certainty further requires rules to be accessible, sufficiently clear, and applied consistently. An order that no one can know before being affected by it can scarcely guide conduct. A rule written to punish a single case can scarcely treat people as equals under a common rule.

The generality of law does not mean ignoring relevant differences. A tax regime may distinguish among activities, and a safety rule may address risk situations. What matters is that the distinction be defined by general, justifiable criteria that can be applied in advance—not by the identity of the person affected or by the convenience of the official on duty.

It is also important to distinguish certainty from immobility. Legal certainty does not prohibit reform; it requires intelligible processes and avoids unpredictably changing the consequences of past actions. Put differently, it protects the ability to organize one’s life without having to guess an authority’s criteria.

Equality and the prohibition of arbitrariness

Equality before the law requires equivalent cases to receive equivalent treatment, unless there is a relevant and articulable reason. The prohibition of arbitrariness adds a demand for justification: power may not decide on the basis of personal preference, hostility, or mere convenience without accounting for the rule applied.

Imagine a city government requiring an additional document only from certain merchants and unable to explain why. The problem does not disappear if that requirement is later presented in a circular. One would have to ask whether it was public, whether it existed before the application, whether it applied to all comparable cases, and whether there is a way to challenge it. Those questions turn an abstract idea into a standard of review.

Key idea: Equality does not require every situation to receive identical treatment; it requires differences in treatment to rest on known rules and reviewable reasons, not favoritism.

Checks among branches and courts able to review

A clear rule is not enough when the same authority that creates, applies, and judges its own decisions faces no counterweights. The separation of powers distributes functions to reduce concentration. It is not an automatic mechanism: it may exist on paper and fail in practice. But it creates channels through which administrative, legislative, or executive decisions are not the last word merely because they come from those in power.

Judicial independence is especially important because it makes impartial review possible. A court must be able to decide according to law and procedure, free from external pressure on the case. Independence does not mean judges stand above every rule or need not give reasons for their decisions. Their powers, procedures, and rulings are also subject to limits.

Access to justice completes the circuit. If a person cannot know the decision affecting them, be heard, present evidence, or appeal to a competent body, the promise of oversight becomes remote. The right of defense makes an institutional limit a concrete possibility for someone facing a penalty, a denial, or state intervention.

Why legality alone is not enough

Legalism often confuses the existence of a rule with the quality of the legal order. A measure may have been approved through a formal procedure and yet leave room for unpredictable, discriminatory, or review-proof decisions. The objection that “the law can oppress too” is valid precisely because it shows why the rule of law cannot be reduced to obedience to legal texts.

To serve as a safeguard against abuse, legality must be accompanied by publicity, generality, equality, procedures, and remedies. This does not make the concept a magic answer to every political disagreement. Rather, it identifies questions power must be able to answer: What rule authorizes the measure? Was it accessible? Was it applied by the same standard? Who can review it? What remedy does the affected person have?

Key idea: A formally legal decision can violate the rule of law if it leaves people without predictable rules, equal treatment, or independent review.

Rule of law, democracy, and constitutionalism: related but distinct concepts

Democracy primarily answers who decides: the people, directly or through representatives and electoral procedures. The rule of law asks under what rules and checks decisions may be made. A majority may approve a measure, but that does not free it from respecting legal limits, equality, and safeguards for dissenters. At the same time, the rule of law does not replace democratic participation: both principles can reinforce one another when majority decisions are made within a framework that protects rights and allows review.

Constitutionalism adds another layer: a constitution may organize powers, recognize rights, and establish higher-order procedures. Liberal constitutionalism has insisted that this architecture serve to limit power and protect freedoms. Yet a constitution by itself does not ensure that the rule of law is effective if its rules are not applied, courts lack independence, or safeguards have no remedy.

Nor should the rule of law be confused with the expression “social state” or with the idea of a constitutional state governed by law. These formulations may describe additional purposes, rights, or constitutional models. The rule of law supplies a cross-cutting question: whatever the public policy, does the authority act under known rules, enforceable limits, and independent checks? Its function is not to decide the content of every policy, but to discipline how power is exercised.

A limit that can be examined

It is not useful to invoke the rule of law as a label for praising or condemning countries without examining specific institutions and cases. Principles indicate what to demand; assessing compliance requires evidence about rules, courts, procedures, and practices. An institutional design may appear sound yet provide inaccessible remedies. A rule may sound equal and be applied selectively.

The concept is useful because it shifts discussion from declared intentions to verifiable conditions. When an authority acts, it is not enough for it to claim to pursue a valuable aim. It must show its competence, the rule that constrains it, the reasons for its decision, and the possibility that an impartial third party can review it.

That demand does not eliminate political conflict or ensure perfect outcomes. It offers something more modest and essential: an order in which people do not depend entirely on the benevolence of those who govern. Freedom and public accountability gain ground when power must explain its acts, obey the same rules it imposes, and accept that it can be corrected.

Sources for further reading

• European Commission: What is the Rule of Law?
• Venice Commission: *Rule of Law Checklist*
• United Nations: What is the Rule of Law?