판례에 나타난 의사능력 유무의 판단기준에 대한 고찰 - 일본에서의 논의와의 비교⋅검토를 중심으로 -

According to precedents, the judgment as to whether there is mental capacity is individually made in relation to specific behavior. There is no formal or uniform standard and a person maintaining that he/she has no mental capacity shall prove it. However, even if the standpoint of a precedent is feasible basically, there shall be certain works to identify the standard as to mental capacity from the perspective of enhancing the national prediction as to the cases where mental incapacity is concretely recognized. In order to conduct such works efficiently, there shall be analyses of precedents and theories as to the judgment of the presence of mental capacity, followed by identification or presentation of a standard of judgment which aim at specification though incomplete. From this perspective, this paper explores Japanese theories and precedents in relation to presence of mental capacity as Japanese legal conditions are most similar to Korean ones. It also applies them to Korean precedents or compares with Korean ones to identify the factors or standard of judgments considered when a precedent decides mental capacity and suggests implications. The paper can be summarized as follows. First, First, the standard of judgment as to the presence of mental capacity in the precedents identified in Japanese theories can be identically applied overall when identifying standard of judgment as to the presence of mental capacity in Korean precedents. This means that alongside uniform standard of judgment as to the presence of mental capacity identified by Japanese theories through analyses of Japanese precedents, most of the specific standards can be applied. Especially, the Supreme Court Decision 2019 Da 213344 Decided May 26, 2022, which expressly maintains for the first time that the level of difficulty and importance of behavior are significant standards to decide mental capacity deserves attention. Second, the decision as to the rationality of motivations, reasons, and backgrounds of certain behavior in a specific standard of judgment on the presence of mental capacity of the precedents identified by Japanese theories does not seem to be proactively used except when judging the presence of mental capacity of the person with an intellectual disability in Korea. However, in the future of Korea, the decision as to rationality shall be proactively considered as a factor or standard when judging the presence of mental capacity. Third, among Japanese theories, there are opinions that the standard of judgment as to the presence of mental capacity in Japanese precedents can be differently identified in terms of degree and scope of recognition depending on the types of persons of mental incapacity. Such opinions suggest that the work to identify the factors or standard of judgment of mental capacity considered when judging mental capacity through precedents is sufficiently meaningful while it is also necessary for Korea. They suggest that the work shall be conducted proactively and from multiple angles. Fourth, in the case of Japan, what was discussed over the consciousness of correlations between the meaning and standard of judgment of mental capacity in the process of revision of the Civil Law in Heisei 29 (2017) needs attention in Korea.