Although numbered, in no particular order:
- Once a fraud, always a fraud.
- Ignorance of the contract is no excuse.¹
- Possession by pirates does not change ownership.
- Things invalid from the beginning cannot be made valid by subsequent act.
- A thing void in the beginning does not become valid by lapse of time.
- Time cannot render valid an act void in its origin.
- Everyone is the manager and disposer of his own matters.
- …
1 In most cases, the use of “contract” is more accurate than “law”.