Chinese sun and moon mirrors being hung round the neck, or because necks are concave things. Liu An's (c. 139 BCE) "Huainanzi" "Masters of Huainan", which is a compendium of writings from various schools of Chinese philosophy, was the first text to record "fangzhu" dew-collectors. Two "Huainanzi" chapters metaphorically use "sun and moon mirrors" to exemplify "yang" and "yin" categories and elucidate the Chinese notion of "ganying" "cosmic resonance" through which categorically identical things mutually resonate and influence each other. The "yángsuì" 陽燧 "burning-mirror" is "yang", round, and sun-like; the "fāngzhū" 方諸 "square receptacle" is "yin", square, and moon-like. The first context describes "yangsui" and
Chinese sun and moon mirrors respond with fire: the pure essence of "yang". When placed before the moon—the ultimate "yin" 陰 phenomenon in the world—they respond with water: the pure essence of "yin". Thus mirrors offer the paradigm for "proper responsiveness": they reflect the true essence of the ultimate "yin" and "yang"—the alpha and omega of phenomena in early Chinese cosmology." (Carr and Ivanhoe 2000: 56) Erin Cline says the early Chinese attributed mirrors to have a mysterious power and great religious significance. The ceremonial bronze "fusui" 夫遂 and "yangsui" 陽燧 mirrors were seen as active, responsive objects because they could be used to produce