Identity of a thing means the sameness in all that constitutes the objective reality of a thing.

Explanation

(English-origin maxim.) To establish identity in law, one must show complete sameness in every material characteristic — a partial resemblance is insufficient where the question is whether two things are truly one and the same.

Where this applies

• A plaintiff claims that a ring found in a pawnshop is her stolen engagement ring, but the court requires her to prove that every material characteristic — cut, setting, engraving, serial number — matches the original, not just that it looks similar.
• A prosecutor must show that the drugs introduced at trial are the exact same substance seized from the defendant, matching in weight, chemical composition, and chain of custody.
• An insurance company disputes a claim by arguing the car in the accident is not the same vehicle listed on the policy, because the VIN, color, and model year do not match.