Part II Performance of the Obligation, 5 Excuses for Failure to Perform on Time

5.01 Excuses for failure to perform may be of various kinds, but in the present context we shall consider them under four headings: (1) exclusions and exceptions; (2) discharge by agreement, variation, waiver and estoppel; (3) prevention by the promisee; and (4) other supervening events. 5.02 A promisor may seek to negative or limit liability by reference to exclusions and exceptions contained in the contract. On the face of it this is a simple matter of construction, but the law has traditionally been suspicious of such clauses, and they therefore merit special...