Define: A Priori Assumption

A Priori Assumption
A Priori Assumption
Quick Summary of A Priori Assumption

In UK law, an “a priori assumption” refers to a foundational belief or presumption that is made before considering specific evidence or circumstances. It is a fundamental principle or starting point that guides legal reasoning and decision-making. A priori assumptions can influence various aspects of the legal process, including statutory interpretation, case law analysis, and judicial decision-making. These assumptions are often based on established legal principles, societal norms, or judicial precedent. While a priori assumptions can provide a framework for legal analysis, they must be subject to scrutiny and revision based on the specific facts and context of each case to ensure fairness and justice in the application of the law.

What is the dictionary definition of A Priori Assumption?
Dictionary Definition of A Priori Assumption

(ah-pree-ory) n. from Latin, an assumption that is true without further proof or need to prove it. It is assumed the sun will come up tomorrow. However, it has a negative side: an a priori assumption made without question on the basis that no analysis or study is necessary, can be mental laziness when the reality is not so certain.

Full Definition Of A Priori Assumption

(ah-pree-ory) n. Derived from Latin, meaning an assumption that does not require further proof that it is true. For example: one assumes that the sun will rise every morning. Mental laziness may occur if the a priori assumption is made without questioning the basis that no analysis or study is required.

A Priori Assumption FAQ'S

In legal contexts, “a priori assumption” refers to fundamental beliefs or premises that are accepted as true without the need for empirical evidence or factual support.


A priori assumptions serve as foundational principles or legal doctrines upon which laws, regulations, and judicial decisions are based, guiding interpretation and application of legal principles.

Examples of a priori assumptions in law include the presumption of innocence, the principle of stare decisis (precedent), and the presumption of regularity (presumption that official acts are performed regularly and in accordance with the law).

Lawyers and judges use a priori assumptions to interpret statutes, apply legal precedents, formulate legal arguments, and make decisions based on established legal principles and doctrines.

Yes, a priori assumptions can be subject to challenge or revision through legal arguments, appellate review, legislative action, or changes in societal norms and values.

A priori assumptions inform statutory interpretation by providing interpretive frameworks and guiding principles for understanding legislative intent and the scope of constitutional rights and obligations.

Yes, unchecked or unjustified a priori assumptions can lead to biases, injustices, and systemic inequalities in the legal system, particularly when they reflect historical biases or societal prejudices.

Legal scholars and theorists critically examine a priori assumptions by analysing their historical origins, philosophical underpinnings, practical implications, and compatibility with principles of fairness and justice.

Yes, challenging entrenched or outdated a priori assumptions may be necessary to advance legal reform, promote social justice, and address inequities or injustices within the legal system.

Yes, a priori assumptions may conflict with empirical evidence or scientific knowledge, leading to tensions between legal principles based on tradition or precedent and evolving societal values or scientific understanding.

Legal systems may adapt to changing societal norms by reinterpreting legal principles, revising laws through legislative processes, or issuing judicial decisions that reflect evolving understandings of justice and equity.

Safeguards such as procedural fairness, judicial review, access to legal representation, and the right to appeal help mitigate the risk of unjust outcomes resulting from unchecked or biased a priori assumptions in legal proceedings.

Related Phrases
A Priori

This site contains general legal information but does not constitute professional legal advice for your particular situation. Persuing this glossary does not create an attorney-client or legal adviser relationship. If you have specific questions, please consult a qualified attorney licensed in your jurisdiction.

This glossary post was last updated: 29th March 2024.

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