Legal Definitions - ad similes casus

Ad similes casus is a Latin legal phrase that historically translates to "to like cases" or "to similar cases." It embodies a fundamental principle in law: that similar situations should be treated similarly. While primarily a historical term, the underlying concept is a cornerstone of modern legal systems, promoting consistency, fairness, and predictability by encouraging judges and legal decision-makers to apply established rules and reasoning to new cases that share essential characteristics with previously decided ones.

Here are some examples illustrating the concept of "ad similes casus":

• Contract Law Example: Imagine a court has previously ruled that a specific type of digital signature, created using a particular software and verification process, is legally binding for online contracts. A new case arises involving a different company but using the exact same digital signature technology and process for its customer agreements. Applying the principle of "ad similes casus," the court would likely treat this as a "like case" and uphold the validity of the digital signature, rather than re-evaluating the technology's legality from scratch. This ensures consistency in how digital contracts are enforced across similar situations.

  Explanation: This example demonstrates how a prior legal determination regarding a specific technology (digital signatures) in one contract case guides the decision in a new, similar contract case, ensuring that "like cases" are decided consistently.

• Administrative Law Example: A city's planning commission has a long-standing policy of denying permits for building structures that exceed a certain height limit in a specific historic district, citing preservation guidelines. When a new developer applies for a permit to build a high-rise apartment building in that same district, the commission, guided by the principle of "ad similes casus," would likely apply its established policy and deny the permit. The new application is a "like case" to previous ones that violated the height restrictions, and treating it similarly maintains the integrity of the historic district's character.

  Explanation: Here, the planning commission applies a consistent rule to similar development proposals within a specific area, ensuring that similar requests are handled uniformly to uphold established policy and preserve the district's character.

• Tort Law (Personal Injury) Example: In a jurisdiction, there's a precedent that a property owner is liable for injuries sustained by a visitor due to a clearly visible, unaddressed hazard (like a broken step) that the owner knew about but failed to fix. A new case emerges where a visitor slips and falls on a different property due to another clearly visible, unaddressed hazard (like a loose handrail) that the property owner also knew about. A judge, following "ad similes casus," would likely apply the same legal reasoning regarding the property owner's duty and liability, as the core facts of a known, unaddressed hazard causing injury are similar, even if the specific hazard differs.

  Explanation: This illustrates how the legal principle of property owner liability for known hazards is applied consistently to different instances of similar negligence, ensuring that individuals injured under comparable circumstances receive similar legal consideration.