The Physiological Society of Japan (PSJ) is one of the oldest medical societies and celebrated its 100th anniversary in 2022. Physiology is the study of the functions and mechanisms of life. The subjects of physiological research range from a single cell to the whole body of various species, as well as from ions, genes, proteins, cells, to human behavior. The ultimate goal of physiology that I believe is to elucidate the fundamental principles of life. In particular, when considering the health of life, it is essential to understand the principles of homeostasis, in which the nervous system, endocrine system, immune system, and others regulate all organ functions. The basic principles of harmonious control of the entire system can be considered the functional essence of a healthy organism. Understanding the fundamental principles of life is required to develop the "biological simulators" and "virtual organisms" in One Health. To achieve this goal, it will be necessary to create a research platform where physiologists, anatomists, pharmacologists, immunologists, neuroscientists, biochemists, and mathematicians bring their knowledge and work together to understand life from the molecular to the systems level in an integrated manner.