Mental weakness - shinshinkoujaku

This refers to cases where a person's mental disability significantly reduces their ability to judge right from wrong (ability to distinguish between right and wrong) or their ability to control their own actions based on this judgment (ability to control their actions). In such cases, the offender is considered to have committed an act of limited responsibility and the sentence is reduced accordingly (Penal Code, Article 39, Paragraph 2). For example, this applies to the acts of people whose judgment and self-control are significantly lower than normal people due to mental illness, intellectual disability, intoxication, drug addiction, sleep, or hypnosis. In contrast, cases where these abilities are lacking are called "insanity" and the offender is considered to have committed an act of a person who is not responsible for his or her own actions and is denied responsibility (Penal Code, Article 39, Paragraph 1). The court ultimately decides whether or not a person is mentally impaired, respecting the psychiatric evaluation by a psychiatrist. The former Penal Code, Article 40, provided that the deaf and mute were found not guilty or had their sentence reduced, but this article was deleted in a partial revision of the Penal Code in 1995. Furthermore, under the Civil Code, a mentally impaired person is a person under guardianship (a quasi-incompetent person under the old Civil Code) and requires the consent of the guardian in order to perform legal acts as stipulated in Article 13 of the Civil Code (however, the term "mentally impaired person" that previously appeared in Article 11 of the Civil Code was amended in 1999 to read "a person whose ability to appreciate truth and reason is significantly insufficient due to a mental disability"), as this term was deemed discriminatory).

[Tetsuro Nawa]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

精神の障害により、善悪を判断する能力（是非弁別能力）またはこの善悪の判断に基づき自己の行動を抑制する能力（行動制御能力）が著しく劣っている場合をいう。このような場合には、限定責任能力者の行為として、刑が必要的に減軽される（刑法39条2項）。たとえば、精神病、知的障害による場合のほか、酩酊(めいてい)、薬物中毒、睡眠や催眠の状態などにより、判断能力や自己抑制能力が通常人よりも著しく劣っている者の行為がこれにあたる。これに対して、これらの能力が欠ける場合を「心神喪失」とよび、責任無能力者の行為として、責任が阻却される（同法39条1項）。心神耗弱にあたるか否かは、精神科医の精神鑑定を尊重して、最終的には裁判所が判断する。なお、かつての刑法第40条は、聾唖(ろうあ)者の行為につき、これを無罪とするか刑を減軽するものとしていたが、1995年（平成7）の刑法一部改正によって、本条は削除された。また、民法上、心神耗弱者は被保佐人（旧民法の準禁治産者）として、民法第13条が定める法律行為をなすにあたっては保佐人の同意を必要とする（ただし、かつて民法11条の条文中にあった「心神耗弱者」の語は、差別的な印象を与えるとして、1999年の改正により、「精神上の障害により事理を弁識する能力が著しく不十分である者」という表現に改められた）。

［名和鐵郎］

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