Zen has been brought to Japan in the 13. century by Zenji Ēsai (Rinzai Zen) and Dōgen Zenji (Sōtō Zen). The teachings core focus is conducted through zaen (sitting meditation), monastic discipline as well as living and learning within a community guided by a teacher. Daily experiences and meditation is more important than theoretical knowledge. Though, Zen is not science, it is not religion, not belief. Zen just is. Sitting in silence, straight posture, focus on breathing, become one with all there is – that is Zen.