Question

what is the difference between res ipsa loquitor and res judicata?

Answer 1

Res ipsa loquitur is a Latin term meaning "the thing speaks for itself". It is a doctrine of law that one is presumed to be negligent if he/she/it had exclusive control of whatever caused the injury even though there is no specific evidence of an act of negligence, and the accident would not have happened without negligence. The traditional elements needed to prove negligence through the doctrine of res ipsa loquitur include:

• The harm would not ordinarily have occurred without someone's negligence
• The instrumentality of the harm was under the exclusive control of the defendant at the time of the likely negligent act
• The plaintiff did not contribute to the harm by his own negligence.

There has been some change in the modern application of the above elements. The "exclusive control" element has been softened in modern cases to a less strict standard, where the plaintiff must prove that other responsible causes, including the conduct of the plaintiff and third persons, are sufficiently eliminated by the evidence. The last element has also softened to a more comparative standard so that if the plaintiff was only 5% negligent in contributing to the accident, the minimal contributory negligence of the plaintiff won't bar a recovery.

For example: "There is a prima facie case that the defendant is liable. The plaintiff was away and had left the house in the control of the defendant. Res ipsa loquitur."

Res judicata is a Latin term meaning "a thing decided". It is a common law doctrine meant to prevent relitigation of cases between the same parties regarding the same issues and preserve the binding nature of the court's decision. Once a final judgment has been reached in a lawsuit, subsequent judges who are presented with a suit that is identical to or substantially the same as the earlier one will apply the doctrine of res judicata to uphold the effect of the first judgment.

Res judicata does not prevent appeals to a higher court and there are limited exceptions to res judicata that allow a party to attack the validity of the original judgment in the same court. These exceptions--usually called collateral attacks--are typically based on procedural or jurisdictional issues, based on the lack of a court's authority or jurisdiction to issue the judgment.