Jewish scholars since the beginning of the common era have developed such restrictive rules to prevent execution of the innocent that the death penalty has become de facto abolished. Moses Maimonides argued that executing a defendant on anything less than absolute certainty would lead to a slippery slope of decreasing burdens of proof, until we would be convicting merely "according to the judge's caprice". His concern was maintaining popular respect for law, and he saw errors of commission as much more threatening than errors of omission.[2] Conservative Jewish religious leaders and scholars believe that the death penalty should remain unused, even in extreme cases such as political assassination.[3]