テーマ

German Thema, written with Th, is the source form for テーマ. Duden traces Thema to Latin thema and Greek thema, the thing set down, from the verb tithenai, to set. The plural in German is Themen, with Themata as a formal variant. 精選版日本国語大辞典 records a music use in 洋楽手引 in 1910 and a literary use in Kikuchi Kan's Mumei Sakka no Nikki in 1918. The word entered Japanese through German academic, music, and arts vocabulary in late Meiji and Taisho education. The 1910 music citation matches Western music education after the 1879 Music Investigation Committee. It first worked well for musical theme, literary subject, discussion topic, and research problem. Japanese also formed mixed or related katakana expressions such as メーンテーマ, サブテーマ, and テーマ曲, with English main or sub placed before the German-derived テーマ. In current Japanese, テーマ means a topic, subject, event concept, or recurring melody. It is close to English theme, but the sound テーマ follows German Thema, not English /θiːm/. 研究テーマを決める means choosing a research topic, a phrase that is more common in Japanese university writing than decide a theme in English.