唐朝的「開元盛世」並不只是社會、政治的歷史事實而已，也是唐詩中特殊的樂 園追尋之主題，當開元盛世逐漸隱沒於歷史之中時，便不斷地在詩歌中以一個新的樂園主題 出現；更正確地說，在安史亂後，「開元盛世」被杜甫以及其他中晚唐詩人視為一個真正的 「往昔的黃金時代」。肇因於對此一「失樂園」的追尋，他們詩中的開元盛世往往被描述為 完善的烏托邦和美麗的世界，充滿了光輝、喜悅、愛情、慶典、音樂、舞蹈和其他種種的藝 術活動，展現出佛萊所謂的「春夏基型」；而另一方面，當這歷史上的美好盛世一去不返時 ，便只留下窮老困蹇的殘餘人物和有如野的蕭瑟景致，符應了「秋冬基型」的表現。這些詩 人在追億活動中運用了四種不同的時間結構， 即：「今 - 昔」、「昔 - 今」、「今 - 昔 - 今」和「今昔交錯」，而無論哪一種，都導向一個殘酷的事實：他們已置身於廢墟中，而 樂園永遠不再。

　　　　　The prosperity of the K'ai-yuan period (開元盛世, 713-741) of the T'ang dynasty existed not only as a socio-political reality in history, but also as a quest-for-paradise theme in T'ang poetry. As the prosperity ofthis period gradually faded into history, it began to appear persistentlyin poetry as a new paradise theme. To be more precise, after the rebellion of An Lu-shan (755), Tu Fu, as well as the Middle and Late Tang poets, regarded this era as an actual "golden past." As a paradise to be emul ated, the K'ai-yiian period is often portrayed in their poems as a utopia-a beautiful world full of light, joy, love, festivals, music, dance and myriad artistic activities. It can be described in what Northrop Frye calls the "spring and summer archetypes." On the other hand, when the prosperous times began to wane, what survived in the poems were often poor, despondent figures and forlorn scenes. This corresponds to what Frye terms the "autumn and winter archetypes. "The poets analyzed here used four kinds of time structure in their reminiscing about the K'ai-yiian period: present-past, past-present, present-past-present and the intermingling of past and present. Nevertheless, regardless of which structure they employed, a cruel reality is immanent: these poets dwell in ruins and long for a lost paradise that will never return.