Which principle does the phrase "nullum crimen sine lege" represent?

The phrase "nullum crimen sine lege" translates to "no crime without law." This principle asserts that an act cannot be deemed a crime unless it has been explicitly defined as such by existing legislation. This highlights the foundational concept in criminal law that individuals cannot be prosecuted for actions that are not clearly delineated as criminal in statutory law. It fosters a sense of legal certainty and protects individuals from arbitrary or capricious prosecution, ensuring that the law is applied consistently and fairly. This principle is crucial in upholding the rule of law, as it requires laws to be clearly defined so that people are aware of what constitutes criminal behavior.