天外救星

拉丁語片語Deus ex machina（英譯：God from the machine）翻譯自希臘語（apò mēkhanḗs theós），意思是機關跑出的神。

在古希腊戏剧，當劇情陷入膠著，困境難以解決時，突然出現擁有強大力量的神將難題解決，令故事得以收拾、有個好結局。扮演神的演員會利用起重機從舞台上方降下，或是起升機從舞台地板的活門抬上。這種表演手法是人為的，製造出意料之外的劇情大逆轉[2]。

這種手法通常被評論家認為是不高明的說書技巧，因為它破壞了故事的內在邏輯，縱使有時候會為了這個理由而故意採用。繼亞里士多德之後，文藝復興時期評論家將其視為一種迂拙的情節計策，雖然其仍然受用於文藝復興時期的劇作家；莎士比亞將此計策用在《一報還一報》《仲夏夜之梦》《皆大歡喜》《泰爾親王佩力克爾斯》和《冬天的故事》[3]。19世紀末，尼采批評歐里庇得斯透過這種計策將悲劇因素製造成樂觀的類型，並促使他高度懷疑戲劇《blissful delight in life》是「希臘快樂」（Greek cheerfulness）[4]。

尼采認為机械降神是蘇格拉底文化的症狀，重視文化知識過於酒神節的音樂並最終導致死亡的悲劇：[5]

But the new non-Dionysiac spirit is most clearly apparent in the endings of the new dramas. At the end of the old tragedies there was a sense of metaphysical conciliation without which it is impossible to imagine our taking delight in tragedy; perhaps the conciliatory tones from another world echo most purely in Oedipus at Colonus. Now, once tragedy had lost the genius of music, tragedy in the strictest sense was dead: for where was that metaphysical consolation now to be found? Hence an earthly resolution for tragic dissonance was sought; the hero, having been adequately tormented by fate, won his well-earned reward in a stately marriage and tokens of divine honour. The hero had become a gladiator, granted freedom once he had been satisfactorily flayed and scarred. Metaphysical consolation had been ousted by the deus ex machina.[6]

尼采認為，机械降神製造出虛假的慰藉感覺，這是不應該尋求的現象，這種情節計策的詆毀普遍出現在評論意見中[7]。一些20世紀的修正主義者的評論，建議deus ex machina不能在簡化的用語中被查看，並主張此種計策是凡人「刺探」與神的關係[8]。拉什瑞姆（Rush Rehm）特別引用希臘悲劇的例子，其中deus ex machina提供複雜化角色的生活和態度，當面臨神的同時為觀眾帶來戲劇的尾聲[8]。

• 轉折（Peripeteia）
• 奇蹟
• 駭客入侵（Deus Ex）