Which legal term refers to the principle that "the thing speaks for itself"?

The term that refers to the principle of "the thing speaks for itself" is res ipsa loquitur. This legal doctrine is often used in tort law to establish negligence. It allows a plaintiff to prove that the negligence of a defendant can be inferred from the very occurrence of the event or injury, without direct evidence supporting the claim. For instance, if a surgical instrument is left inside a patient after surgery, the circumstances imply that something went wrong due to negligence, which is evident from the nature of the incident itself.

On the other hand, primo facie refers to evidence that is sufficient to establish a fact unless disproven, while stare decisis is the legal principle of determining points in litigation according to precedent. Ex post facto relates to laws that change the legal consequences of actions that were committed before the laws were enacted. Understanding these distinctions is essential for grasping the nuances of legal terminology and principles in the context of medical law and ethics.