Legal Definitions - bursting-bubble theory

The bursting-bubble theory is a principle in evidence law that describes how certain legal assumptions, known as presumptions, function in a legal proceeding. A presumption is an assumption of fact that the law requires to be made from another fact or group of facts that have been established.

Under this theory, a legal presumption acts like a temporary placeholder. It establishes a fact as true unless and until credible evidence is presented that contradicts it. Once such contradictory evidence is introduced, the "bubble" of the presumption "bursts." This means the presumption disappears, and the party who initially benefited from it can no longer rely on that assumption. Instead, they must now actively prove the fact in question through evidence, just as if the presumption had never existed.

• Example 1: Presumption of Mail Delivery

  Imagine a business dispute where one party claims they sent a crucial contract amendment by mail. The law often includes a presumption of mailing, meaning if a letter is properly addressed, stamped, and placed in the mail, it is presumed to have been delivered to the recipient. This presumption acts as the initial "bubble."

  However, if the recipient then presents credible evidence, such as a sworn statement that they never received the letter, or a tracking record showing it was returned to sender, this contradictory evidence "bursts" the bubble. The presumption of delivery disappears. The party claiming to have sent the amendment can no longer simply rely on the assumption that it was received; they must now present actual proof, like a signed return receipt or an email confirmation, to convince the court that the amendment was indeed delivered.

• Example 2: Presumption of Child Legitimacy

  In family law, if a child is born to a married woman, there is often a strong legal presumption that the husband is the biological father. This presumption is designed to protect the family unit and the child's status, acting as the initial "bubble."

  However, if the husband later presents credible evidence to the court, such as DNA test results conclusively proving he is not the father, or testimony from the wife admitting to an affair and naming another biological father, this evidence "bursts" the bubble of legitimacy. The presumption no longer holds. The court would then consider all the presented evidence to determine paternity, rather than simply assuming the husband is the father.

• Example 3: Presumption of Competence

  When an adult enters into a contract or makes a will, there is a legal presumption that they are mentally competent to understand their actions and the consequences. This presumption of competence is the initial "bubble," meaning the law assumes individuals have the capacity to make their own decisions.

  If, however, someone challenges the validity of the contract or will and presents credible evidence that the person lacked mental capacity at the time – perhaps medical records indicating severe dementia, or expert psychiatric testimony – this evidence "bursts" the bubble. The presumption of competence disappears. The party seeking to uphold the contract or will can no longer rely on the assumption of competence; they must now present evidence to affirmatively prove that the individual was indeed competent when they signed the document.