unaware of the incapacity of the other, and the state of the afflicted party is
not apparent, then the contract will be regarded as a contract between two
parties of sound mind. In this case a sale of land was held binding because
the buyer did not realise that the seller suffered from a mental disability.
The situation in Hart v O’Connor is in practice unlikely to arise often,
and is an example of the courts taking an objective and reasonable
approach, and looking for external evidence of agreement. The law here is
in line with criminal law, where a defence of intoxication may only be used
in limited circumstances. In both cases the court must be convinced of the
genuineness of the arguments, and it is unlikely that much sympathy would
be felt towards a party using deliberate excessive drinking to escape an
unwanted contract.
The principles regarding those with mental disability are now restated in
s. 7 of the Mental Capacity Act 2005.
Diplomats and sovereigns
This category of limited capacity exists to protect those who work on
behalf of their country, and to enable international relations to proceed
unfettered by problems of ignorance of foreign law. In practice it is only
seen actively in minor incidents, apart from an isolated group of more high
profile cases.
Capacity 79But not:- corporations
- drunkards
- those of unsound mind
- diplomats and sovereigns
- minors
Most adults have full
contractual capacityFigure 5.1