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Prima facie

Prima facie is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Prima facie rather than just read about it. In short: Prima facie (; from Latin prīmā faciē) is a Latin expression meaning "at first sight", or "based on first impression". The literal translation would be "at first face" or "at first appearance", from the feminine forms of primus ("first") and facies ("face"), both in the ablative case.

Prima facie — main illustration
Prima facie — illustration

Key takeaways

  • Prima facie belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Prima facie to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Prima facie from memory before moving on to harder problems.

Reference excerpt

Prima facie (; from Latin prīmā faciē) is a Latin expression meaning "at first sight", or "based on first impression". The literal translation would be "at first face" or "at first appearance", from the feminine forms of primus ("first") and facies ("face"), both in the ablative case. In modern, colloquial, and conversational English, a common translation would be "on the face of it". The term prima facie is used in modern legal English (including both civil law and criminal law) to signify that upon initial examination, sufficient corroborating evidence appears to exist to support a case. In common law jurisdictions, a reference to prima facie evidence denotes evidence that, unless rebutted, would be sufficient to prove a particular proposition or fact. The term is used similarly in academic philosophy. Most legal proceedings, in most jurisdictions, require a prima facie case to exist, following which proceedings may then commence to test it, and create a ruling. The similar ex facie, Latin for "on the face [of it]," is a legal term typically used to note that a document's explicit terms are defective without further investigation. For example, a contract between two parties would be void ex facie if, under a legal system where it was a binding requirement for validity, the document did not require party A to give consideration to party B for services rendered.

Burden of proof

In most legal proceedings, one party has a burden of proof, which requires it to present prima facie evidence for all of the essential facts in its case. If it cannot, its claim may be dismissed without any need for a response by other parties. A prima facie case might not stand or fall on its own; if an opposing party introduces other evidence or asserts an affirmative defense, it can be reconciled only with a full trial. Sometimes the introduction of prima facie evidence is informally called making a case or building a case. For example, in a trial under criminal law, the prosecution has the burden of presenting prima facie evidence of each element of the crime charged against the defendant. In a murder case, this would include evidence that the victim was in fact dead, that the defendant's act caused the death, and that the defendant acted with malice aforethought. If no party introduces new evidence, the case stands or falls just by the prima facie evidence or lack thereof, respectively. Prima facie evidence does not need to be conclusive or irrefutable: at this stage, evidence rebutting the case is not considered, only whether any party's case has enough merit to take it to a full trial. In common law jurisdictions such as the United Kingdom and the United States, the prosecution in a criminal trial must disclose all evidence to the defense. This includes the prima facie evidence. An aim of the doctrine of prima facie is to prevent litigants from bringing spurious charges which simply waste all other parties' time.

Res ipsa loquitur Prima facie is often confused with res ipsa loquitur ('the thing speaks for itself', or literally 'the thing itself speaks'), the common law doctrine that when the facts make it self-evident that negligence or other responsibility lies with a party, it is not necessary to provide extraneous details, since any reasonable person would immediately find the facts of the case. The difference between the two is that prima facie is a term meaning there is enough evidence for there to be a case to answer, while res ipsa loquitur means that the facts are so obvious a party does not need to explain any more. For example: "There is a prima facie case that the defendant is liable. They controlled the pump. The pump was left on and flooded the plaintiff's house. The plaintiff was away and had left the house in the control of the defendant. Res ipsa loquitur." In Canadian tort law, this doctrine has been subsumed by general negligence law.

Use in academic philosophy

The phrase is also used in academic philosophy. Among its most notable uses is in the theory of ethics first proposed by W. D. Ross in his 1930 book The Right and the Good, often called the Ethic of Prima Facie Duties, as well as in epistemology, as used, for example, by Robert Audi. It is generally used in reference to an obligation. "I have a prima facie obligation to keep my promise and meet my friend" means that the speaker is under an obligation, but this may yield to a more pressing duty. A more modern usage prefers the title pro tanto obligation: an obligation that may be later overruled by another more pressing one; it exists only pro tempore.

Other uses and references

The phrase prima facie is sometimes misspelled prima facia in the mistaken belief that facia is the actual Latin word; however, faciē is in fact the ablative case of faciēs, a fifth declension Latin noun. In policy debate theory, prima facie is used to describe the mandates or planks of an affirmative case, or, in some rare cases, a negative counterplan. When the negative team appeals to prima facie, it appeals to the fact that the affirmative team cannot add or amend anything in its plan after being stated in the first affirmative constructive. A common usage of the phrase is the concept of a "prima facie speed limit", which has been used in Australia and the United States. A prima facie speed limit is a default speed limit that applies when no other specific speed limit is posted, and may be exceeded by a driver; however, if the driver is detected, and cited by police for exceeding the limit, the onus of proof is on the driver to show that the speed at which the driver was travelling was safe under the circumstances. In most jurisdictions, this type of speed limit has been replaced by absolute speed limits.

See also

Advisory speed limit Defeasible reasoning List of Latin phrases Probable cause Proximate cause

References

Further reading Audi, Robert (2003). Epistemology: A Contemporary Introduction (Second ed.). Routledge. p. 27. Herlitz, Georg Nils (November 1994). "The Meaning of the Term Prima Facie". Louisiana Law Review. 55 (2): 391.

Worked examples

Example 1 — a first encounter with Prima facie

Start with the simplest possible case. Write down what Prima facie claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Prima facie before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Prima facie ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Prima facie

In research
Prima facie appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Prima facie in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Prima facie is common in secondary-school and first-year university syllabi. It links to neighbouring topics Common law, Latin legal terminology, Latin logical phrases, so understanding it makes those chapters shorter.
In everyday life
Look for Prima facie outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Prima facie in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Prima facie means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Prima facie out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Prima facie in simple terms?

Prima facie (; from Latin prīmā faciē) is a Latin expression meaning "at first sight", or "based on first impression". The literal translation would be "at first face" or "at first appearance", from the feminine forms of primus ("first") and facies ("face"), both in the ablative case.

Why does Prima facie matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Prima facie?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Prima facie.

Tags

  • Common law
  • Latin legal terminology
  • Latin logical phrases
  • Latin philosophical phrases
  • Legal reasoning

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