Courts attempt to give meaning to the parties’ understanding when they wrote the contract.
The intention of the parties governs, and if their purpose in making the contract is known or can be ascertained from all the circumstances, it will be given great weight in determining the meaning of an obscure, murky, or ambiguous provision or a pattern of conduct. A father tells the college bookstore that in consideration of its supplying his daughter, a freshman, with books for the coming year, he will guarantee payment of up to $350. His daughter purchases books totaling $400 the first semester, and he pays the bill. Midway through the second semester, the bookstore presents him with a bill for an additional $100, and he pays that. At the end of the year, he refuses to pay a third bill for $150. A court could construe his conduct as indicating a purpose to ensure that his daughter had whatever books she needed, regardless of cost, and interpret the contract to hold him liable for the final bill.