What principle is NOT associated with Roman law?

The correct choice highlights a principle that is not typically associated with Roman law. Roman law is known for establishing a range of legal principles that laid the foundation for many modern legal systems, including concepts such as "innocent until proven guilty," which emphasizes the presumption of innocence in legal proceedings. Additionally, the principle of non-retroactivity of law means that laws cannot be applied to actions that occurred before the law was enacted, thus protecting individuals from being judged under laws they were unaware of at the time of their actions.

The right to a fair trial was also a significant aspect of Roman legal proceedings, ensuring that defendants had the opportunity to present their cases and defend themselves. In contrast, the protection of the ignorant is not a defined principle within Roman law. While Roman law did have mechanisms to address the consequences of ignorance in some contexts, it did not universally provide an overarching protection for individuals who were unaware of legal standards or rules.

Thus, the lack of an established principle in Roman law specifically aimed at protecting the ignorant distinguishes this choice as the correct answer.