Tongshu 通書 "The book of the universality", original title Yitong 易通 "The universal range of the Changes", also called Lianxi tongshu 濂溪通書 or Zhouzi tongshu 周子通書, is a book of Zhou Dunyi 周敦頤 (1017-1073), a Neo-Confucian philosopher of the Northern Song period 北宋 (960-1126). The book is usually brought into relation with Zhou's cosmology as described in his Taiji tushuo 太極圖說. It is divided into 40 brief chapters.
The Tongshu is a development of philosophical teachings of the ancient Classic Zhongyong 中庸 "The Golden Mean", enriched by cosmological ideas as found in the commentary parts of the Classic Yijing 易經 "Book of Changes" called Yi dazhuan 易大傳. Zhou was of the opinion that all beings on earth (wanwu 萬物) were inherently endowed with the spirit of Heaven, or "the originary [power] of the hexagram Qian" (qianyuan 乾元, for hexagrams see Yijing). Expressed in human comportment, this spirit was sincerity (cheng 誠). Sincerity was thus seen as the basic element of the five Confucian virtues (wuchang 五常), namely kindness (ren 仁), righteousness (yi 義), rites (li 禮), wisdom (zhi 智), and trust (xin 信). Sincerity was also the ground for the "hundred actions" (baixing 百行) in human life.
Zhou explains that Heaven used the force of the "energy" or "potential" Yang 陽 to give birth to the ten thousand beings, while the potential of Yin 陰 was able to complete them (tian yi yang sheng wanwu, yi yin cheng wanwu 天以陽生萬物，以陰成萬物). Transferred to human behaviour and moral aspects, "giving birth" meant kindness (sheng, ren ye 生，仁也), while "completion" meant righteousness (cheng, yi ye 成，義也). All humans were thus given the ideal forms of Confucian moral values by birth, and had the potential to use them in all their aspects, and to rise from "bad" to average and even to moral perfectness. The perfect man (shengren 聖人) – as a private person or as a ruler – was able to discard all improper desires (wu yu 無欲) and to "dwell in quiescence" (jing chu 靜處).
Matter or substance per se was either in a state of movement (dong 動), or in a state of quiescence (jing 靜). These two conditions were moving in constant cycles. Objects (wu 物), including plants, animals, and humans, were either in a status of movement or in that of stillness. Yet the cosmological sprit (shen 神) behind things was immovable within movement, and restless within rest (dong er wu dong, jing er wu jing 動而無動，靜而無靜) - this was the spirituality of the Utmost Extreme.
Zhu Xi 朱熹 (1130-1200) wrote the commentary Tongshu jie 通書解. The imperial series Siku quanshu 四庫全書 includes Cao Duan's 曹端 (1376-1434) commentary Tongshu shujie 通書述解. The text is found in the collected works of Zhou Dunyi, Zhouzi quanshu 周子全書, Zhou Yuangong ji 周元公集 or Zhou Lianxi ji 周濂溪集.