We are constantly being in uenced and acted upon by various people, creatures and things, in other words, by beings outside our bodies. Taking Spinoza’s concept of ‘Affectus’ as a base, this book is an attempt by thirteen specialists from various fields, including anthropology, Japanese painting, primatology, cognitive psychology and philosophy, to present their work from the perspective of Affectus.
From a foray into the forest to study bonobos that lead to the author’s experience of gradually resonating with the rhythms emitted by the forest, changing his senses to the point that he became able to identify the myriad of forest sounds, to descriptions of a large drum player showing his creativity and improvising only when he is affected by the precise rhythms that the cymbals and small drums chime in, and to the contemporary world of Japanese chess, where human players and AI interact and in uence each other’s game play, the authors of this book present a new affective world view.
Complex intrinsic forces, ‘outside of us’, are felt to exist, but are invisible, unpredictable, and different from oneself. We both wait for and accept something that comes from the outside, and somehow live that Outside. Reviewing our experiences from the Affectus perspective reveals a new world.

Ayako Iwatani (Chapter 6) is a professor at the Graduate School of Human and Environmental Studies, Kyoto University. She graduated from the doctoral course of the graduate school in 2005. After working as an associate professor at Hiroshima University, she assumed her current position. She holds a PhD in human and environmental studies. Her specialties and interests are cultural anthropological research on ‘Gypsies’/ Roma and memory of diasporic communities.

Naoki Kasuga (Chapter 8) is professor emeritus at the School of Human Sciences, Osaka University, and the School of Social Science, Hitotsubashi University. He served as a professor at each of these universities from 1996 2010 and 2010 17, respectively. He holds PhD in human sciences, specializes in anthropology and is interested in identity and symmetry for humans.

Kazunori Kondo (Chapter 11) has been associate professor at the Graduate School of Human Sciences, Osaka University, since 2023. He was associate professor of Law, Economics and the Humanities Area at Kagoshima University. He holds a PhD in human sciences, and specializes in contemporary philosophy, epistemology of science and the history of French philosophy.

Akinori Kubo (Chapter 9) is a professor at the Graduate School of Social Science, Hitotsubashi University, after serving as a full-time lecturer. He holds PhD in human sciences. His major fields are anthropology of technology; cultural anthropology; and science, technology and society.

Suehisa Kuroda (Chapter 2) is a professor emeritus of the University of Shiga Prefecture. He was a professor of the university from 1995 to 2013. He has a PhD in science, and specializes in primate sociology, anthropology and regional cultural studies.

Kyoko Nakamura (Prelude) is a Japanese painter. She is an associate professor at Osaka University Nakanoshima Art Center, a fellow at the Research Institute for Languages and Cultures of Asia and Africa, Tokyo University of Foreign Studies, and an invited researcher at Waseda Research Institute for Science and Engineering. She graduated from the Japanese Painting Course at Tokyo University of the Arts in 2005, and completed the doctoral course of its graduate school in 2010. She has a PhD in art, and specializes in Japanese painting and art theory.

Katsuo Nawa (Chapter 7) is professor at the Interfaculty Initiative in Information Studies, Graduate School of Interdisciplinary Information Studies, and at the Institute for Advanced Studies on Asia, both in the University of Tokyo. He graduated from the university’s doctoral course at the Graduate School of Area and Sciences in 1999 and holds a PhD. After serving as associate professor and professor at the Institute for Advanced Studies on Asia, the University of Tokyo, he assumed his current position in 2020. He specializes in cultural anthropology, linguistic anthropology and ethnography of the Himalayan region and South Asia.

Ryoko Nishii (Editor, Preface, Acknowledgements, Introduction, Chapter 3) is a professor at the Research Institute for Languages and Cultures of Asia and Africa, Tokyo University of Foreign Studies. She holds a PhD in literature. Her specialties and interests are anthropological fieldwork, ethnography of affect and the anthropology of death.

Akira Okazaki (Chapter 4) has been a fellow at the Research Institute for Languages and Cultures of Asia and Africa, Tokyo University of Foreign Studies, since 2015. He completed a doctoral course at the School of Oriental and African Studies, University of London in 1997 and holds a PhD. He specializes in social anthropology and African studies. He was a special fellow of All Souls College in the University of Oxford, an assistant professor at Kanagawa University, a visiting professor at the Institute of Ethnology, Leipzig University, and a professor at the Graduate School of Social Sciences, Hitotsubashi University.

Yukio-Pegio Gunji (Chapter 12) is a professor at the Department of Intermedia Art and Science, Waseda University, and professor emeritus at Kobe University. He received his PhD from the Graduate School of Science, Tohoku University, in 1987 and has been in his current position since 2014. He specializes in theoretical biology and natural intelligence.

Yutaka Sakuma (Chapter 5) is an associate professor at the School of Political Science and Economics, Meiji University. He was assistant professor at the Research Institute for Languages and Cultures of Asia and Africa in the Tokyo University of Foreign Studies. He holds a PhD and specializes in cultural anthropology and African regional studies.

Kotaro Takagi (Chapter 10) is professor at the School of Social Informatics, Aoyama Gakuin University. After working as an assistant at the Graduate School of Education, the University of Tokyo, and as a lecturer and associate professor at the Center for Research in International Education, Tokyo Gakugei University, he assumed his current position in 2008. He specializes in developmental psychology, cognitive psychology and legal psychology.

Tadashi Yanai (Editor, Acknowledgements, Introduction, Chapter 1, Conclusion) has been a professor at the Graduate School of Arts and Sciences, the University of Tokyo, since 2013. He received his PhD from the University of Tokyo in 1993. He was a visiting professor at the University of Barcelona, and an associate professor at Tenri University and the Graduate School of the University of Tokyo. He specializes in the anthropology of images and of nature, as well as philosophy.