讽喻与昭雪:《步辇图》李德裕题跋考论

Allegory and exoneration:On Li Deyu’s postscript attached to Emperor Taizong Receiving the Tibetan Envoy

北京故宫博物院藏《步辇图》手卷,是记录初唐贞观年间禄东赞入朝为松赞干布请婚事件的一件美术作品。该图卷旧传为阎立本手笔,后流传至晚唐,大和年间李德裕重予裱褙,并题跋于画心左侧。既往的研究,多集中在画作为唐真迹还是宋摹本、作者为谁、所呈现的具体历史场景为何以及递藏等方面,李德裕重装褙并题跋的动机、功能及影响,则鲜有学者论及。文章从跋文的格式、《册府元龟》的录文两个方面,为原跋文出于李德裕之手提供了新的佐证;通过对重装褙背景及跋文的分析,发现此事隐射了晚唐与吐蕃关系的一桩旧事——吐蕃维州城守将悉怛谋受降事。由于牛僧孺、李宗闵等人的打击报复,李德裕在该事件中经历了政治与道德的双重失败,其所遭受的“幽枉”或羞辱,乃是其政治生涯中最刻骨铭心的记忆,故始终在寻找辩白和昭雪的机会。2年后,他主持中枢,恰逢宫廷书画整理与收藏活动,此时他新伤未平、恨意难抒,遂以宰相之尊亲自主持《步辇图》的重装褙工作,并不厌其烦、喋喋为之题跋。该题跋,与其说是对约200年前太宗接见禄东赞事件的追忆,毋宁是对2年前他本人所受的政治羞辱的咀嚼;同时,该题跋也可索解李德裕在剑南西川节度使任职时的遭遇、他所倡导的边疆政策及二者与题跋内容之间隐喻性的关联。具体地说,其题跋所表现的内容,或不仅引发了李德裕的身世之痛,也可赋予其所主张的边疆政策以历史的正当性。跋文对《步辇图》所表现的事件进行了重构,似是为暗示他对维州受降事件的处理,乃是遵循太宗皇帝的原则和遒谟;而文宗皇帝与牛李出卖向化者致其遭虐杀,则违背了太宗所确立的对帝国藩属的执驭之道。换言之,李德裕对《步辇图》的题跋,当是以对太宗朝贞观旧事以及吐蕃政策的征引为隐喻,暗讽维州城悉怛谋受降事,并为自己辩白。重装褙、题跋及“追论悉怛谋”等一系列事件,不仅解慰了12年来所遭受的良心之痛与道德折磨,反映了当时牛李两党对于吐蕃政策的不同主张,在一定程度上,也折射了中晚唐朝廷对于回鹘、黠戛斯等边疆民族割据政权的立场及策略。文章可作为探讨古人如何以书画收藏及题跋活动作为政治“动源”,来隐晦地表达其施政策略的美术史个案。

Emperor Taizong Receiving the Tibetan Envoy, a hand-scroll traditionally attributed to Yan Liben(601—673), is a contemporary visual documentation of the diplomatic encounter between Tang and the kingdom of Tibet, immediately after the later was defeated and accepted tributary status in 641 AD. In 833, nearly two centuries after the encounter, Li Deyu(787—849), the chief minister of the court, ordered the hand-scroll to be remounted and wrote a postscript at the end of it, which recounted the encounter in a new perspective. Previous studies have mostly focused on whether the painting is an authentic work of the Tang Dynasty or a copy of the Song Dynasty, who the author is, what the specific historical scenes it presents, and its collection history, but few scholars have discussed the motivation, function and influence of Li Deyu’s remounting and postscript. This paper provides new evidence that the original postscript was written by Li Deyu from two aspects: the format of the postscript and the book of Prime Tortoise of the Record Bureau;Through the analysis of the background and new postscript, it reflects a border incident between Tang and the kingdom of Tibet that Xidamou who was the defender of Weizhou City, a general of the kingdom of Tibet, surrendering to the Tang Dynasty. Due to the revenge of Niu Sengru, Li Zongmin and others, Li Deyu experienced the failure of politics and morality in this event. The injustice or humiliation he suffered was the most unforgettable memory in his political career, so he was always looking for opportunities to plead and defend himself. Two years later, when he came to power, he met the sorting and collection activity of calligraphy and painting in the court. At this time, he did not recover from the new injury or expresse his hatred yet, so, he presided over the remounting of the Emperor Taizong Receiving the Tibetan Envoy and did not tire of making postscripts. The postscripts are not a memory of the Taizong meeting with Lu Dongzan about 200 years ago, but an expression of the political humiliation he suffered two years ago;meanwhile, the postscripts also indicated Li Deyu’s experience when he served as the Jiannan Xichuan Jiedushi, and the frontier policy he advocated. To be specific, the content of his postscripts may not only cause his pain for his fate, but also give historical legitimacy to his frontier policy. The postscripts reconstructed the events shown in the Emperor Taizong Receiving the Tibetan Envoy seems to imply that his handling of the surrender of Weizhou followed the principles and strategies of Taizong;However, emperor Wenzong, Niu Sengru and Li Zongmin betrayed those who surrendered and caused them to be tortured and killed, which violated the strategy how the empire controlled tributary states established by Taizong. In other words, Li Deyu’s postscripts to the Taizong Receiving the Tibetan Envoy took advantage of the past events in the Taizong Dynasty and the policy to the kingdom of Tibet as a metaphor, secretly satirized the surrender of Weizhou city, and defend himself. A series of events, such as remounting the scroll, writing down postscripts, and asking emperor Wuzong to grant Xidamou an official post, not only relieved the pain of conscience and moral torture suffered in the past 12 years, but also revealed the different opinions of the Niu and Li parties on the policy to the kingdom of Tibet at that time. To a certain extent, it also reflected the position and strategy of the mid and late Tang court on the separatist regimes of Uyghurs, Xiajiasi, and other frontier ethnic groups. This paper is an art history case to explore how the ancients used calligraphy and painting collections as well as inscriptions as political agency to implicitly convey their administrative strategies.