Law is a rigorous science. At any time, you cannot rely solely on perceptual and experience, but must rely on reason and logic. It is necessary to use a given "standard caliper" to check and measure, and not to use personal simple emotions as the laws. Because draconian laws are also laws, and laws are related to simple emotions, but they are not always consistent.
Why is it said that evil laws are also laws? Because the evil here is only the evil evaluated by people subjectively, not the evil with objective standards, and in fact there is no good and evil with objective standards. As the "Tao De Jing" puts it, the world knows that beauty is beautiful and evil is already; everyone knows that good is good, but that is bad. Because there is no objective standard of good and evil, what one person thinks of evil may not be evil in the other's eyes; what is evil today may not be evil in tomorrow's eyes, because good and evil are mutual. Transformed. Because good and evil are problems of dialectical logic, and law is only a problem of formal logic, the problem of good and evil cannot be directly applied to law, just as dialectical logic cannot be directly applied to formal logic. Just as it cannot be said that right and wrong coexist, whether there is a coexistence, and good and evil are one, then it is judged that a person who has done something wrong or has committed a crime is not guilty or not wrong. This is because although dialectical logic is appropriate in the field of dialectical logic, it cannot be applied in the field of formal logic, nor is it applicable. Although, fact finding is dialectical and dynamic, there are good and evil. But the application of norms is static in form and there is no good or evil. This is called static braking. If the facts are dynamic and the norms are also dynamic, then dynamic braking will result in chaos and confusion.
法律是一门严谨的学问，任何时候都不能只凭感性和经验，而必须得依靠理性和逻辑。必须要用给定的“规范卡尺”去卡、去度量，而不能以个人的朴素情感为法。因为恶法亦法，法与朴素情感有联系，但并不总是一致。
为什么说恶法亦法？因为这里的恶只是人们主观评价的恶，而非具有客观标准的恶，而且实际上也并不存在一个具有客观标准的善与恶。正如《道德经》所言，天下皆知美之为美，斯恶已；皆知善之为善，斯不善已。因为并不存在一个善与恶的客观标准，所以一个人认为的恶，在另一个人看来可能并不恶；今天看来的恶，在明天看来可能并不恶，因为善恶本来就是相互转化的。
因为善恶是辩证逻辑上的问题，而法律只是形式逻辑上的问题，所以善恶的问题不能直接适用用于法律，正如辩证逻辑不能直接适用于形式逻辑。就如不能说，对错是并存的、有无是相生的、善恶是一体的，就裁判一个做错事、犯了罪的人没有罪或没有错。因为虽然辩证关系在动态复杂的辩证逻辑的论域是适当的，但在静态简单的形式逻辑的论域内就不能适用，也是不可适用的。
那为什么在法本身的善、恶上，承认有动态辩证关系，而在法的具体适用上又不接受这种动态辩证关系了呢？因为法的认定与事实认定一样，都是事实问题，虽然事实认定是动态辩证、存在善恶的，但法的适用或规范的适用却是静态简单、没有善恶的。而这实际上就是以静制动，而之所以要以静制动。因为如果事实认定是动态的，规范适用也是动态的，那就是以动制动，就会乱套，就会无所适从。
