一般而言,「脈絡」或「客觀歷史情境」往往被視為是「政治行動」的條件,然而,政治行動反過來卻又可以是轉化客觀情境的因素。兩者之間於是形成一種循環辯證的關係。本文試圖依據拉克勞與慕英所發展出來的後結構主義論述理論來重新探討這一關係。對拉克勞與慕英而言,所有的社會實踐,包括政治行動,都是論述實踐。他們採取了政治優位性的立場,藉由分析論述結構的不穩定性(即「社會」的不可能性)來強調「偶然性邏輯」(這種邏輯與「發然性邏輯」長久處於一種不對等關係)的重要性,並將結構決定論以及種種對於超驗主體或特定社會行動者的預設予以破除,而以「社會」與「政治」的相互作用來重新界定政治行動及其可能性條件之間的關聯。
While ”contexts” or ”objective historical conjunctures” are generally taken as the conditions of political actions, the latter signify the possibility to transform the former hence a dialectical or circular relationship. This paper attempts to re-examine this relationship from the perspective of Laclau and Mouffe's discourse theory. For Laclau and Mouffe, social practices, including political actions, are discursive and articulatory practices. They postulate the primacy of the political over the social, and emphasize the significance of the logic of contingency (vis-avis the logic of necessity). Through their rejection of structural determinism and the category of transcendental subject, and their analysis of the radical undecidability of discourse formation, i.e., the impossibility of ”society,” Laclau and Mouffe re-define the relationship between political actions and their conditions of possibility in terms of the mutual constitutiveness between the social and the political.