Our society is changing rapidly, and laws and legal systems must be created or modified to keep pace with these changes. As a result, laws are created or existing laws are amended. Criminal laws are no exception, and the role of creating and amending these laws lies with the legislature in accordance with the principle of separation of powers. As the members of the legislature are politicians, they are required to distinguish between their legislative and political activities. However, legislation is becoming a political tool as national demands, such as the demand for safety from crimes, are approached from a political perspective. Accompanying this phenomenon are a number of problems, such as overlapping legislations, symbolic legislations, and the excessive special laws, which are exceptions to the principles of general laws. The legislative tendency in creating or amending criminal statutes is to follow the severe punishment principle, which caters to populism. In other words, strong penalties and punishments are reflected in legislation in order to maximize political purposes and effects. However, this does not take into account the basic principles of criminal law, and problems can arise with the coherence and legitimacy of the legal system. Furthermore, the tendency of the symbolism and severe punishment principle, which takes advantage of populism, treats offenders as potential criminals. In terms of legal economics, strengthening punishments may be of limited use in preventing dangers and crimes. In addition, criminal laws serve to regulate criminal sanctions and is the most powerful sanctioning instrument because it uses imprisonment and fines, which restrict the freedom of the body and property rights. Therefore, the use of criminal law should be a last resort; however, the frequency of the use of criminal sanctions to guarantee the effectiveness of administrative acts in the area of administrative legislation, which is not covered by the existing criminal laws, is increasing. Criminal legislation must consider the principles of proportionalism and responsibility. However, actual criminal legislations do not seem to consider these principles sufficiently because of the abovementioned reasons. Therefore, for reasonable criminal legislation, it is necessary to first consider amending laws that are faithful to the general principles of criminal law, that do not violate the Constitution, and that can meet the demands of social change. For this purpose, the issues of culpability and the integrity of the legal system must be considered in concrete terms. If these requirements can be satisfied, some of the proactive functions of reasonable criminal legislation can be performed to a certain extent, and the limitations that may remain can be improved at a later time.