《周易參同契》是想藉由外煉服食和引內養性雙管齊下的方式，來達到後天返先天的效果。可以說，外煉服食是想直接造成身體的轉化，而引內養性則是想透過心性的提昇並帶動身體的轉化。總而言之，在這兩者加乘作用的帶動下，以期同時造成身體與意識的提昇轉化，而達致神仙的先天境界。而內養和外煉的一體性之工夫論基礎，是建基在元氣論這個存有論和世界觀。另外，《周易參同契》雖然承繼了《易傳》那種宇宙生成論的天地陰陽之論述，與及運用其象數觀念和漢代所形成的數術對應系統；但是《周易參同契》畢竟不同於《易傳》那種儒家式的立場，亦即它的終極目標並非要在於天地這個時空場域中去建構歷史文化，而是要從天地這個現象場域回歸先天地的本體場域。

In order to transcend the houtian 後天 and return to the xiantian 先天, the Zhou Yi cantongqi 周易參同契 combines two kinds of practical methods: alchemical diet (waidan/ fushi 外丹/服食) and spiritual meditation (yinnei yangxing 引內養性). In other words, an alchemical-metallic diet was believed to be able to transform the body, while Wei Boyang 魏伯陽 also asserted that this could be achieved via spiritual meditation. In sum, Wei Boyang expected to transform the body and consciousness concurrently through two different methods with the final goal being to reach the Gods’ Xiantian Paradise (shen­xian xiantian leyuan 神仙先天樂園). The two practical methods stemmed from the same source, which was based upon the ontology of the primary qi (xiantian qi 先天氣 or yuanqi 元氣). In addition, the Zhou Yi cantongqi inherits both the yinyang cosmogony (yinyang zhouyu shengchenglun 陰陽宙宇生成論) from the Book of Changes and the symbolic-mathematic skills and mathematical-correlative system (shushu duiying xitong 數術對應系統) from the Han dynasty. However, the Zhou Yi cantongqi possesses a different standpoint than the Confucian one of the Book of Changes, as its ultimate goal neither was based on the ontic field nor constructed historical culture. Instead, it aimed at transcending the phenomenal plane of the houtian and return to the ontological realm of the xiantian.