# Latin Maxims — Expanded

Maxims still in active use in Canadian legal practice, with usage notes.

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## Procedural and Structural

**Ex parte** (without notice)
Proceeding heard without notice to the other side. In modern practice
generally disfavoured except for genuine emergency remedies (Anton Piller
orders, Mareva injunctions) or where the rules explicitly permit.

**Inter partes** (between the parties)
Proceeding heard on notice to and with participation of all parties. The
default.

**In camera** (in chambers)
A proceeding held in private, not in open court. Reserved for narrow
circumstances (child protection, some criminal matters, sensitive
personal information).

**In personam** (against the person)
A right, remedy, or judgment operating against a specific person.
Equitable remedies are traditionally in personam.

**In rem** (against the thing)
A right, remedy, or judgment operating against a thing or against the
world. Admiralty proceedings and certain property claims are in rem.

**Sub judice** (under judgment)
A matter currently before a court. Commenting on sub judice matters may
raise contempt concerns.

**Nunc pro tunc** (now for then)
A retroactive order treating a past act as done at the correct time.
Used to correct procedural irregularities.

**Sine die** (without a day)
Without a specific future date. An adjournment sine die means adjourned
indefinitely.

**Pro tem** or **pro tempore** (for the time being)
Temporarily. A judge pro tempore is a temporary judge.

**Ex officio** (from the office)
By virtue of one's office. An ex officio member of a committee is a
member because of their position.

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## Evidentiary and Substantive

**Prima facie** (at first appearance)
Evidence sufficient to establish a fact unless rebutted. A prima facie
case is one that would succeed if unmet.

**Res ipsa loquitur** (the thing speaks for itself)
An inference of negligence permitted where the harm is one that does
not ordinarily occur without negligence and the instrument was under the
defendant's exclusive control.

**Res judicata** (a matter judged)
The doctrine barring re-litigation of matters already decided between
the same parties. Comprises cause of action estoppel and issue estoppel.

**Res gestae** (the thing done)
The doctrine treating certain statements made during or immediately
after an event as admissible as part of the event itself. Modern
Canadian practice largely absorbs this into the principled approach to
hearsay.

**Nemo dat quod non habet** (no one gives what they do not have)
The general rule that a transferor cannot transfer better title than
they hold. Subject to statutory and equitable exceptions.

**Caveat emptor** (let the buyer beware)
The common-law rule that the buyer bears risk of quality. Substantially
displaced by consumer protection legislation and implied statutory
warranties.

**Volenti non fit injuria** (to a willing person, no injury is done)
The defence of voluntary assumption of risk. Narrow in modern practice —
requires full knowledge of the risk and genuine acceptance.

**Ex turpi causa non oritur actio** (no cause of action arises from an
illegal act)
The doctrine barring a plaintiff from recovering where their claim
depends on their own illegal conduct.

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## Interpretive

**Ejusdem generis** (of the same kind)
The rule that a general term following a list of specific terms is
limited to things of the same kind. "Cats, dogs, and other animals" —
"other animals" limited to domestic animals.

**Expressio unius est exclusio alterius** (the express mention of one is
the exclusion of others)
The rule that express mention of certain things suggests the exclusion
of unmentioned things.

**Noscitur a sociis** (known by its associates)
The rule that a word's meaning is coloured by the surrounding words.

**Generalia specialibus non derogant** (general terms do not derogate
from specific terms)
Where a general provision conflicts with a specific one, the specific
prevails.

**Contra proferentem** (against the offeror)
The rule that an ambiguous term is construed against the party who
drafted or introduced it. A last-resort rule in contract interpretation.

**A verbis legis non est recedendum** (one must not depart from the words
of the law)
The plain meaning canon. Now substantially subsumed within the modern
approach to statutory interpretation.

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## Criminal Law

**Actus reus** (guilty act)
The physical element of a criminal offence. Includes conduct,
circumstances, and consequences as required by the offence definition.

**Mens rea** (guilty mind)
The mental element of a criminal offence. Categories include intention,
knowledge, recklessness, and (for regulatory offences) negligence.

**Nulla poena sine lege** (no punishment without law)
The principle that criminal punishment requires a legal basis. Related
to the rule against retroactive criminal law.

**Nemo debet bis vexari pro una et eadem causa** (no one should be twice
vexed for the same cause)
The principle against double jeopardy. Constitutionalized in Canada
under Charter s.11(h).

**Ignorantia juris non excusat** (ignorance of law does not excuse)
The general rule that mistake of law is not a defence. Subject to narrow
exceptions (officially induced error, s.19 Criminal Code discussion).

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## Adjudicative Principles

**Nemo judex in causa sua** (no one may be judge in their own cause)
The rule against bias in adjudication. A core component of natural
justice and procedural fairness.

**Audi alteram partem** (hear the other side)
The right to be heard. A core component of procedural fairness. Includes
the right to notice of the case to be met and an opportunity to respond.

**Ratio decidendi** (the reason for the decision)
The binding legal principle of a case. Distinguished from obiter dicta.

**Obiter dictum** (said in passing)
A judicial statement not necessary to the decision. Persuasive but not
binding. Plural: obiter dicta.

**Stare decisis** (to stand by things decided)
The doctrine of binding precedent. Vertical stare decisis (lower courts
bound by higher) is strict; horizontal (courts bound by their own prior
decisions) is qualified.

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## Property and Title

**Bona fide purchaser for value without notice** (good-faith purchaser)
A purchaser who acquires legal title in good faith, for consideration,
without notice of prior competing interests. Protected from most
equitable claims against the property. Sometimes abbreviated "BFP" or
"equity's darling."

**Sui generis** (of its own kind)
A unique category, not fitting standard classifications. Some
Aboriginal title claims have been described as sui generis interests.

**Quantum meruit** (as much as he deserved)
The reasonable value of services rendered where no contract fixes the
price. Basis for certain restitutionary claims.

**Cy-près** (as near as possible)
The doctrine that a charitable purpose that fails may be redirected to
the nearest possible alternative purpose.

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## Miscellaneous

**Bona fide** (in good faith)
Genuinely and honestly. Contrast mala fide.

**Mala fide** (in bad faith)
Dishonestly, with improper motive.

**Sine qua non** (without which not)
A necessary condition. Used in causation analysis.

**Mutatis mutandis** (with the necessary changes being made)
Applying the same principle with the necessary adaptations.

**Habeas corpus** (you shall have the body)
The writ requiring a person detained to be brought before a court to
test the legality of the detention. Constitutional protection under
Charter s.10(c).

**Amicus curiae** (friend of the court)
A person appointed by the court to assist on a point of law or to
represent an interest not otherwise represented.

**Ipse dixit** (he said it himself)
A bare assertion without support. Used to characterize an argument as
lacking evidentiary basis.

**Pro bono publico** (for the public good)
Used to describe legal work done without fee for public benefit. Usually
abbreviated "pro bono."

**Ad hoc** (for this)
For this particular purpose. An ad hoc committee is one formed for a
specific task.

**Ad hominem** (to the person)
An argument directed at the person rather than the argument itself.
Fallacious in most contexts.

**A priori** (from what comes before)
Based on reasoning from prior principles, without empirical evidence.

**A posteriori** (from what comes after)
Based on empirical evidence, after the fact.

**De facto** (from the fact)
In reality, as a matter of fact, whether or not legally recognized.

**De jure** (from the law)
By right, as a matter of law.

**De minimis non curat lex** (the law does not concern itself with
trifles)
The doctrine that minor infractions or minute quantities do not attract
legal consequence.

**Force majeure** (superior force)
A term in contracts allocating risk of supervening events beyond the
parties' control. Not strictly a common-law doctrine but a widely used
contractual concept.

**Inter alia** (among others)
Among other things. Used to signal that a list is not exhaustive.

**Quid pro quo** (something for something)
Consideration; something given in exchange.

**Ultra vires** (beyond the powers)
An act done beyond the authority of the person or body doing it.

**Intra vires** (within the powers)
An act done within the authority of the person or body doing it.

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## Discipline on Latin

Use Latin maxims only where:

1. They compactly express a doctrine you're actually invoking
2. Your reader will understand them (or you translate)
3. They add precision, not decoration

Overuse of Latin reads as pretentious in modern practice. Well-placed
Latin reads as precise. Know the difference.