 Zhang’s “Western Inscription” inspired Confucians throughout East Asia to develop philosophical thinking about their oneness with the natural world and its generative being, and to advance practical thinking about how to respectfully engage with the realm of heaven and earth. In Tokugawa Japan, this environmental concern took many forms. Kaibara Ekken’s Plants of Japan (Yamato honzō), a kind of botanical study of Japanese medicinal plants and herbs, is one example. In his Instructions of Cultivating Life (Yōjōkun), Ekken emphasized the importance of nourishing one’s ki, or generative force, in harmony with that of all between heaven and earth. Equally important, especially as an indicator of the perennial significance of Zhang Zai’s “Western Inscription” is Kumazawa Banzan’s (1619–1691) “Western Inscription for Japanese” (Yamato nishi no mei), an expansive, vernacular commentary on Zhang Zai’s brief text. In his Questions and Answers on the Great Learning (Daigaku wakumon), Banzan outlined various policy proposals, including limits on the construction of Buddhist temples and samurai castles, as a means of preventing deforestation. He also declared mountains, forests, and rivers – metaphors for the natural world – to be the foundations of the state, and essential components in the longevity of political lines. If a ruler forfeited these components of nature and his realm’s balance with the natural world, then his line would pay the price. Banzan’s writings reveal that even Confucians in the private sector were thinking proactively about achieving a sustainable equilibrium with the forces of nature, one that provided for both the best interests of human society and the integrity of natural growth and development.