What does the "parol evidence rule" mean in Texas contract law?

The "parol evidence rule" in Texas contract law fundamentally pertains to the admissibility of oral statements and other external evidence in relation to a written contract. Specifically, the rule restricts the use of evidence that contradicts or alters the terms of a written agreement. This means that if a contract has been reduced to writing, prior or contemporary oral negotiations or agreements that seek to modify or contradict the written terms cannot be introduced in court to change the meaning of that written contract.

This rule is grounded in the intention to provide certainty and clarity to contractual obligations and to uphold the integrity of written agreements. Parties are encouraged to fully express their agreement in the written document, ensuring that the contract reflects their complete and final understanding. The rationale behind this is to prevent confusion and disputes regarding the parties’ intentions and to uphold the reliability of written agreements as a clear representation of the parties' commitments.

The other options imply different principles, such as incorrectly suggesting that oral agreements can override written terms, that all contracts must be in writing to be enforceable, or that witness testimony can be introduced without limitation. However, these concepts do not accurately reflect the purpose and function of the parol evidence rule in Texas contract law. Thus, the correct understanding revolves around the restriction on