Legal Definitions - ambiguitas patens

Term: ambiguitas patens

Ambiguitas patens refers to an ambiguity that is obvious and apparent on the face of a legal document, such as a contract, will, or statute. It means the language used in the document is inherently unclear, contradictory, or makes no sense when read by itself, without needing any outside information or context to reveal the confusion. Because the ambiguity is so evident, courts generally do not allow external evidence (like witness testimony about what the parties intended) to clarify it, as doing so would be seen as rewriting the document rather than interpreting its original meaning.

Here are some examples illustrating ambiguitas patens:

• Example 1: A Conflicting Will Clause

  A clause in a will states: "I leave my entire collection of antique watches to my nephew, John, or my niece, Mary."

  Explanation: This statement presents an immediate and obvious ambiguity. The use of "or" between John and Mary makes it impossible to determine from the will itself which beneficiary the testator intended to receive the watches. The document's language is directly contradictory regarding the recipient, making it a clear case of ambiguitas patens.

• Example 2: A Contract with Inconsistent Deadlines

  A construction contract specifies: "The project must be completed by June 1st, but also states that the final payment will be made upon completion, which is scheduled for August 1st."

  Explanation: Here, the contract contains two conflicting deadlines for completion. One clause indicates June 1st, while another implies an August 1st completion for final payment. This contradiction is evident simply by reading the contract, creating an ambiguitas patens regarding the actual completion date and the terms of payment.

• Example 3: A Property Description with Contradictory Instructions

  A property deed describes a boundary line as: "Starting at the old oak tree, the boundary runs due north for 100 feet, then turns due west to the river. However, a subsequent sentence states the boundary also runs due south for 50 feet from the old oak tree."

  Explanation: This deed presents an ambiguitas patens because the description of the property boundary is internally inconsistent. It simultaneously directs the boundary to run north and south from the same starting point, making it impossible to determine the correct boundary line from the document's text alone. The conflict is apparent without needing to visit the property or consult other records.