Legal Definitions - cujus contrarium est verum

cujus contrarium est verum

This Latin phrase translates to "the contrary of which is the truth."

In legal contexts, this principle is used to assert that if a particular statement or claim is proven to be false, then its direct opposite must necessarily be true. It applies in situations where there are only two mutually exclusive possibilities, meaning that disproving one automatically establishes the other as fact.

Here are a few examples to illustrate this concept:

• Contractual Performance Dispute:

  Imagine a construction contract where a clause states, "Final payment is due only upon the successful completion of all safety inspections." The contractor submits an invoice, claiming all safety inspections have been successfully completed. However, the client presents evidence, such as official inspection reports, showing that several critical safety inspections actually failed.

  How it illustrates the term: The contractor's assertion that all inspections were successfully completed is proven false. Applying cujus contrarium est verum, the legal conclusion is that the *contrary* – that not all safety inspections were successfully completed – is the truth. Therefore, the condition for final payment has not been met.

• Alibi in a Criminal Case:

  In a trial for a robbery that occurred at 10:00 PM, the defendant provides an alibi, testifying under oath that they were at home, asleep, at the time of the crime. The prosecution then presents compelling evidence, such as security camera footage placing the defendant at a different location miles away at 9:55 PM, and cell phone records showing active usage from that same location at 10:05 PM.

  How it illustrates the term: The defendant's claim of being home asleep is directly contradicted and proven false by the evidence. According to cujus contrarium est verum, the *contrary* – that the defendant was *not* home asleep, but rather at a different location – is accepted as the truth. While this doesn't automatically prove guilt, it discredits the alibi and removes a key defense.

• Regulatory Compliance Claim:

  A manufacturing company applies for an operating license, stating in its application that its waste disposal system fully complies with all federal environmental regulations. During a pre-licensing audit, environmental inspectors discover significant design flaws and operational deficiencies in the system that clearly violate multiple regulatory standards.

  How it illustrates the term: The company's initial claim of full compliance is found to be false. Therefore, by the principle of cujus contrarium est verum, the *contrary* – that the waste disposal system *does not* fully comply with federal environmental regulations – is established as the truth, leading to the denial of the operating license until the issues are rectified.