The objective theory of contracts means that we view mutual assent and the other elements of contracts from an objective, rather than subjective, perspective. We do not care what the subjective and unstated intent of a particular party is. We are concerned with what the party did to the other party and whether a reasonable ordinary person would have interpreted those actions as an intention to contract.
On the terms of the contract, the same is true. We look at what the ordinary person would have interpreted the contract terms to mean. Unless there is a specific definition of the terms in a contract, we use the ordinary dictionary definition of the terms.
Can you think of reasons why we use the objective theory of contracts?