“天降塔”辨析

“Devāvatāra Stūpa” Reconsidered

在成熟的藏传佛教善逝八塔建筑体系中,塔座部分设四层阶级、各面当中凸出并设阶梯的类型被称为"天降塔",阶梯被比拟为纪念佛在忉利天为母说法后降下阎浮提时所踏的三道宝阶。"天降塔"并非根据印度的某座塔所仿建,而是塔所体现的象征体系的重构。藏传佛教后弘期早期西藏西部流行四面具阶梯的塔,照此标准被认定为天降塔。在当时,这种塔与忉利天降下的佛传情节显然并没有直接的联系,因此现阶段把它们视作"具阶梯塔"更为确切。方形塔基的具阶梯塔最早见于犍陀罗,随着犍陀罗佛教文化的传播,也见于阗、龟兹、梵衍那和迦湿弥罗等地。西藏西部的地理位置与上述地方邻近,文化交流的结果之一就是涌现出具阶梯塔,这可以解释为何同时期在卫藏以及受藏传佛教强烈影响的西夏等地区很少看到这种塔的影子。根据文献可知,具阶梯塔的阶梯象征四圣谛或四不护,是塔的重要构件。天降塔最初形成之时,其建筑形制借鉴了包括西藏西部在内的内陆亚洲流行的具阶梯塔,而为了强化它与忉利天降下故事的呼应关系,阶梯改用并列的三道,这也可以看作具阶梯塔与真正意义上的天降塔的一个分水岭。

Of the eight types of stupas, the structure characterized by four steps around the base and(a) flight(s) of stairway(s) in the middle of each side is usually called Devāvatāra Stūpa(Tib. lha babs mchod rten), or Decent Stupa in English, whose design are compared to the three stages of stairways along which the Buddha descends from the Thirty-three Heaven to Sā?ka?ya after presentation. However, its design is no imitation of any pagodas in India, but a reconstruction with a combination of systematic symbols. It is called 'Devāvatāra Stūpa' by its style after the stupa designed with a flight of steps on each side in the western Tibet, which enjoyed great popularity during the early phyi dar period of Tibetan Buddhism. Therefore, it is appropriate to call it ‘strupa with stairway' because it had nothing to do with Buddha's descent at that time. The stūpa based on a square pedestal with stairway in front or on each side was created in Gandhara, then appeared in Khotan, Kucha, Bamiyan, Kashmir which were geographically close to west Tibet in which there were many stūpas of the same style, but rare in central Tibet or other areas, under the impact of Tibetan Buddhism, such as Tangut Xia. As historical archives record, the steps which play a key part in the construction of a stūpa are symbol of the 'Four Nobel Truths' or the 'four points that need no guarding'(Skt. catvāry arak?ya?i). The early Devāvatāra Stūpa was designed after the west Tibetan and inner Asian stūpas with stairways. The architectural design with one flight of stairs was gradually adapted into three flights of stairs alongside on each side with intention of strengthening the link between this kind of stūpa and the story about the Buddha's descent, which may be thought of as a divide between the stūpa with stairways and genuine Devāvatāra Stūpa.