reasonable

The word “reasonable” in law means fair, proper or moderate having regard for the circumstances. It is most frequently used as a word fixing a standard of assessment. Use of the word imports an objective test with the noun with which it is used.

The word is used in a plethora of different contexts in law; such as “reasonable price”, “reasonable person”, “reasonable time” or “reasonable force”.

In the context of the law of negligence, a reasonable person is a hypothetical person used as a legal standard to determine whether the claimant has breached their duty of care to the defendant in the particular case, by failing to take reasonable care. The use of the word “reasonable” introduces concepts of ordinarily expected degrees of intelligence, knowledge, attentiveness and judgement. Such a person will act with proper but not excessive precautions, sensibly, and does things without serious delay, in the circumstances. In this way, notions and standards of behaviour and responsibility correspond with those generally obtained by ordinary people.

The meaning of the phrases is the same mutatis mutandis in contract law.

For instance:

1. a reasonable person may be assumed to have conducted a search of the Register of Trade Marks prior to using a trade mark in the course of their business;
2. a reasonable person might be said to have conducted reasonable enquiries in respect to the ownership of title prior to entering into a contract for the sale of land;
3. Supposing a contracting party was entitled to exercise a contractual right "acting reasonably". The use of the express words (supposing such words were not implied into the contract in any event), would likely import an obligation on the party looking to exercise the right to not exercise it capriciously.