《西遊記》小說的收束，並未讓讀者對真經「勸化眾生」的效應有所信服，因此激發了明清續書的創作。《西遊補》在「火焰芭蕉」及「洗心掃塔」中間插入一「婉孌近人」的鯖魚世界，而綜觀行者迷失於「夢想顛倒」的幻境，似乎使得故事反過來從九頭駙馬的墮落開始閱讀亦無不可。《續西遊記》始於對孫悟空「機變心」的嚴苛檢視，但妖魔的層出不窮，使得作者只能乞靈於「淡漠不動」的消極手段，這也讓這趟重返長安的旅程充滿了諷刺。至於《後西遊記》「求解」的行動，成果完全為「佛妖」所竊占，宣告破產；反而是大顛師徒途中所遭遇的妖魔，充滿了擇「惡」固執的殉道精神。《西遊記》的明清三種續書，側面揭櫫了「心是病，魔是藥也」的弔詭敘事，書中的妖魔書寫，或可視為對道德意識的深沉叩問。

While the ending of Journey to the West cannot convince readers of the effect of the Tripiṭaka on saving the world, it inspired the creation of sequels in the Ming and Qing Dynasties. A Supplement to the Journey to the West adds the appearance of the Mackerel Spirit in the middle of the Flaming Mountains and the Kingdom of Jisai. Because of the feature of "distorted dream-thinking" in this sequel, readers may turn into the story from the theft of the Nine-Headed Prince Consort. A Sequel to the Journey to the West begins with a rigorous examination of Sun Wukong's "Mechanical Heart", but the endless emergence of demons makes the author can only deal with it with absolute negativity, which also makes this journey back to Chang'an full of irony. In The Later Journey to the West, the achievement of pursuing "true interpretation" was finally stolen and occupied by the demons within Buddhism, which is a complete failure. On the contrary, the demons encountered by the Dadian Monk and his apprentices during their travels are full of the spirit of martyrdom who choose "evil" stubbornly. The Ming-Qing sequels of Journey to the West show the paradox of "The Heart is a Disease, the Devil is a Medicine". The descriptions of the demons in the three novels can be regarded as an in-depth question about moral consciousness.