Legal Definitions - index animi sermo

index animi sermo is a Latin maxim that translates to "speech is the index of the mind." In legal contexts, this principle asserts that the specific words and language used in a document are the most reliable and direct evidence of the author's or drafter's true intentions.

It emphasizes that when interpreting a law, a contract, a will, or any other legal instrument, the explicit language chosen by its creator should be given primary importance. The assumption is that the words were chosen deliberately to convey a particular meaning, and therefore, those words best reflect the underlying intent.

• Contract Interpretation: Imagine a business contract between a software developer and a client. A clause states, "The developer shall deliver the final product by December 31st." The developer delivers on January 5th, arguing that they understood "shall" to mean "should aim to" rather than a strict deadline.

  Applying index animi sermo, a court would focus on the precise word "shall." In legal drafting, "shall" is typically understood to impose a mandatory obligation, not a suggestion. The explicit choice of "shall" over less definitive terms like "should" or "may" clearly indicates the parties' intent for a firm deadline, making the developer's argument less persuasive.

• Will and Testament: Consider a will that includes the provision, "I bequeath my entire collection of antique timepieces to my nephew, David." After the testator's passing, the executor discovers a valuable collection of vintage fountain pens and wonders if these also pass to David.

  Under the principle of index animi sermo, the court would strictly interpret the language "antique timepieces." The testator specifically mentioned "timepieces" and did not include "fountain pens" or "other collectibles." The clear and precise language used in the will indicates an intent to bequeath only the timepieces to David, not the pens.

• Statutory Interpretation: A local ordinance prohibits "the discharge of any firearm within city limits." A resident is cited for firing a pellet gun in their backyard, arguing that a pellet gun is not a "firearm" in the traditional sense, which usually refers to weapons that use gunpowder.

  A court applying index animi sermo would examine the term "firearm." If the ordinance's drafters intended to restrict only gunpowder-based weapons, they could have used more specific language like "powder-actuated firearms." By using the broader term "any firearm," the language suggests an intent to prohibit a wider range of projectile-launching devices, including pellet guns, to ensure public safety. The chosen words reflect the legislative intent.