Abstract
On February 13, 2012, the Supreme Court of Japan handed down a ruling on the unlawful disclosure of confidential information committed by a physician, relating to the criminal case commonly known as "the leak scandal during the investigation for the arson and murder case in Nara prefecture." This decision examined whether or not an act committed by a physician who has been ordered to conduct an expert examination and make a medical determination (including diagnosis based on his/her knowledge and experience as a physician) and who discloses, without justifiable grounds, another person's confidential information, constitutes the crime of unlawful disclosure of confidential information under Article 134 of the Japanese Penal Code. Diverging from Japanese legal history, the concurring opinion of the decision cites the Hippocratic Oath, which provides a judicial explanation for confidentiality, while also providing an ethical perspective. This article considers how the scope of legal confidentiality has changed, by examining the introduction of ethical perspectives made after this decision. Ultimately, in the aforementioned case, the Supreme Court of Japan adopted the argument that a relationship of mutual trust is not a necessary legal requirement for the crime of revealing a secret to be committed. Because the argument was explained from a relatively ambiguous ethical perspective, the scope of legal confidentiality has been expanded considerably, so that it now covers not only the disclosure of confidential information, but also that of any person other than the subject of the expert examination which the physician has come to know in the course of said expert examination. The present article provides a critical analysis of this judicial opinion, asserting that to understand the limits of the legal duty of confidentiality, it is indeed necessary to discern whether or not such a relationship of mutual trust exists. Analyzing the leading case concerning the legal duty of confidentiality, as well as the commentary upon it, this article finally argues that it is necessary to reconsider the relationship between law and ethics (or morality) from the perspective of legal positivism.
