“Nemo plus iuris ad alium transferre potest quam ipse habet.”
As intimidating as that old Roman law adage sounds, it has a very simple and common‑sense meaning:
No one can transfer more rights to another than he himself has.
Often referred to as the nemo plus iuris rule, it was formulated by one of Rome’s great jurists, Ulpian, and nearly eighteen centuries later it is still quoted in our modern courts. If you don’t own a house, a car, or any asset you are “selling,” you can’t transfer ownership. With a few narrow exceptions, that principle still forms part of South African law today.
But this is just one of many Latin maxims that lawyers rely on – not to sound clever, but because these ancient phrases capture core legal ideas in only a few words.
Below are a few more, explained in plain English for everyday understanding.
Other Latin Maxims People Encounter More Often Than They Realise
1. Audi alteram partem – “Hear the other side”
No one should be judged without being given a fair chance to explain their case. It’s the foundation of procedural fairness — from school disciplinary hearings to High Court trials.
2. Nemo iudex in causa sua – “No one may be a judge in his own cause”
You can’t decide a matter if you stand to benefit from the outcome.
If you’re involved, you must step aside. It’s a basic rule against bias.
3. Ignorantia juris non excusat – “Ignorance of the law is no excuse”
Not knowing something is illegal won’t protect you.
The law assumes we all have a duty to familiarise ourselves with the rules that govern society.
4. Pacta sunt servanda – “Agreements must be kept”
Once you’ve signed a contract, you’re bound by it.
This is the backbone of contract law: we honour what we commit to.
5. Res ipsa loquitur – “The thing speaks for itself”
Used in negligence cases where the facts are so obvious that the negligence is presumed.
Example: A hospital instrument left inside a patient after surgery.
6. Volenti non fit injuria – “To one who consents, no injury is done”
If you willingly take on a risk, you generally can’t later claim damages for harm arising from that risk.
Think of contact sports or signing up for an activity with known dangers.
7. Onus probandi – “The burden of proof”
Whoever makes an allegation must prove it.
In criminal cases, this rests squarely on the State — the accused doesn’t have to prove innocence.
8. Caveat emptor – “Let the buyer beware”
Buyers must take care and make reasonable checks themselves.
While consumer protection laws soften this rule today, the principle is still important in private sales.
9. De minimis non curat lex – “The law does not concern itself with trifles”
Courts don’t waste time on petty or insignificant matters.
A grievance too small to matter in practice usually won’t get legal relief.
10. Habeas corpus – “You shall have the body”
A fundamental safeguard against unlawful detention.
It compels authorities to bring a detained person before court to justify keeping them locked up.
11. Ut res magis valeat quam pereat – “Interpret things so they work rather than fail”
Courts prefer an interpretation that makes a contract or statute effective, not meaningless.
Common sense trumps overly literal interpretations.
12. In pari delicto potior est conditio defendentis – “Where both parties are equally at fault, the defendant’s position is stronger”
If both sides engaged in wrongdoing, the law generally won’t help either of them.
It’s the legal version of: “You both caused this mess.”
13. Lex specialis derogat legi generali – “The specific law overrides the general law”
When two legal rules conflict, the more specific one usually wins.
For example, a specific statute on housing will trump a general statute on municipal regulations.
14. Qui prior est tempore potior est iure – “First in time, stronger in law”
Where two people claim the same right, the one who acquired it first usually prevails.
Often applied in property and security rights.
15. Falsus in uno, falsus in omnibus – “False in one thing, false in everything”
If a witness deliberately lies about one important point, their entire testimony may be viewed with suspicion.
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