「咸」的本義為皆、悉、都。而〈咸卦〉之咸為交感、感通之義，之所以命名為「咸」，蓋取無心之感、相感之道、相互交感、無所不感等義。〈咸卦〉於《易》六十四卦中，為第三十一卦，為下經之首。上經以〈乾卦〉、〈坤卦〉為首，下經以〈咸卦〉、〈恆卦〉為首，蓋因上經始天道，下經始人倫之故。〈咸卦〉的主旨，從廣義來看是普遍闡明事物「感應」之道。從狹義來看，是側重取義於男女「交感」之道。卦中蘊含的超出男女「交感」之外的「天地感而萬物化生，聖人感人心而天下和平」的思想，是值得重視的《易》哲學體系中「宇宙化生」、「聖人教化」理論的一端。〈咸卦˙卦辭〉稱感應誠正則亨，取女吉。六爻從「足趾」開始，未言吉凶；「小腿肚」，妄動則凶，安居則吉；「大腿」，泛隨有吝；「心臟」感於「心神」，守正至吉；「背脊」未能廣應，僅得「无悔」；「輔頰」感應轉微，無誠則吉凶難測

”Xian” of original meaning is all and all and all. The Xian of Xian Gua is to hand over the etc. meanings of the feeling, feeling. Named after ”Xian”, because of not intentional feeling, mutually the way of feeling, hand over feeling and have no mutually not feeling etc. meanings. The Xian Gua is the 31th in 64 Guas. Top through with dry Gua and Kun Gua for head, descend through with Xian Gua and Heng Gua for head, be in order to ascending through since God's way, bottom through since ethical relations of reason. The subject of Xian Gua, see from the broad sense is widespreadly clarify the way that the thing responds. Seeing from narrow sense, it is the way that inclines toward men and women to hand over feeling. Contain in the Gua of outrun the thought that the men and women hand over ”world and creation turn to get, sage public and world peace” out of the feeling, Be worth valuing Yi-King ”the universe turns to get”, ”sage culture” ories in philosophy system of a carry. The Xian Gua Gua Ci thinks to respond truly just positive then, matrimony is okay. Six Yaos is since ”toe”, don't say good and bad; ”Calf' moves in disorder not good, nestle good then; ”Thigh”'s following behind in disorder will regret; ”Heart” feeling is at the heart, heart just good then; ”Spine” can't extensively respond, can just without the regrets; ”Cheeks” responds to diminish, have no sincerity then the Ji Xiong Be difficult to measure