Le 「ma」 est, depuis quelques décennies, un concept dont il est assez souvent question dans les textes portant sur le Japon. Tel le kanji qui le représente, soit un pictogramme qui montre le soleil qui perce entre les deux battants d’une porte, le 「ma」 exprime un entre-deux dynamique et porteur de sens. Après un premier chapitre qui explore les liens entre langue et culture au Japon, quatre chapitres sont consacrés au 「ma」, un premier qui présente un état des lieux, un second qui explore ses précurseurs ainsi que ses formes disciplinaires, sauf en musique et en architecture, traités au chapitre suivant, alors que le dernier chapitre tente de cerner et de définir le 「ma」, et qu’une annexe survole ce qu’il en est en Occident. Le sixième chapitre de la thèse présente la dichotomie 「内・外 uchi-soto」, marqueur premier de l’appartenance à tout groupe au Japon, incluant la nation. Suit un chapitre portant sur la frontière entre le uchi et le soto de la nation japonaise, puis un autre qui explore les formes que prend l’identité nationale japonaise. Le dernier chapitre offre une synthèse. Il en ressort que : - le 「ma」 est un concept associé à un terme importé au début de l’âge classique, mais ce n’est qu’à la transition entre le 戦国 sengoku (mi 15e à fin 16e) et l’ère 江戸時代 Edo (1600-1868) que les conditions seront réunies pour permettre la naissance du concept. Celui-ci restera toutefois presque purement disciplinaire jusqu’à 昭和 Shōwa (1926-1989), après quoi il prendra des formes qu’on peut qualifier d’identitaires, d’abord en opposition à l’Occident au début Shōwa, puis comme ambassadeur d’une identité japonaise consolidée à partir des années 1960. / The concept of 「ma」 has, for the last several decades, been mentioned quite often in texts on Japan. Like the kanji that represents it, a pictogram showing the sun piercing between the two leaves of a door, 「ma」 expresses a dynamic and meaningful in-between. After a first chapter exploring the links between language and culture in Japan, four chapters are devoted to 「ma 」, a first one which presents a portrait of 「ma 」, a second which explores its precursors as well as its disciplinary forms, except in music and in architecture, treated in the next chapter, while the last chapter attempts to identify and define 「ma」, and an appendix covers what has happened in the West. The sixth chapter of the thesis presents the 「内・外 uchi-soto」 dichotomy, the primary marker of belonging for any group in Japan, including the nation. Follows a chapter on the border between the uchi and the soto of the Japanese nation, then another one that explores the forms that Japanese national identity takes. The last chapter provides a synthesis. It is concluded that : - 「ma」 is a concept associated with a term imported at the beginning of the classical age, but it is only at the transition between the 戦国 sengoku (mid 15th to late 16th) and the 江戸時代 Edo era (1600-1868) that the conditions for the birth of the concept were met. However, it remained almost purely disciplinary until 昭和 Shōwa (1926-1989), after which it took forms that can be qualified as identity carriers, first in opposition to the West at the beginning of Shōwa, then as the ambassador of a consolidated Japanese identity from the 1960s. - 「ma 」 is now clearly linked to Japanese national identity, but it never became a star of national identity. It has certain qualities that would perhaps allow it to become one one day, including its links to several artistic disciplines, most of which, moreover, are traditional, but it also has characteristics that could be a problem, notably the difficulties in rationalizing it. - 「ma」 seems to have developed only in Japan, yet it represents a universal reality. The existence of the concept, however, has certainly helped to frame the apprehension of this reality better than without it, thus facilitating its reappropriation in a variety of artistic fields. - 「ma」 represents relatively well the buffer dynamics that one finds at the border between the uchi and the soto of the nation, but the reality is way more complex than what a model resulting from a simple concept would allow. - 「ma」 is not a fundamental and timeless element of Japanese nature, but clearly arose in a specific context, with favourable conditions which might just as well never have happened.