印順長老的兩部大作──《初期大乘佛教之起源與開展》與《印度佛教思想史》，以「佛滅後，佛弟子對佛的永恆懷念」作為大乘起源與開展之原動力，搏得了臺灣學界一致的認同。然而，該書所提出的論證，似乎仍不足以成立此一命題。因此在本文中，筆者擬另闢蹊徑，嘗試從人類更深廣的集體潛意識中去探尋大乘興起的心理動力。 首先，筆者假設：初期大乘經典之思想型態與佛弟子的心理需求是相呼應的。如果某一思想型態之經典愈多且愈受重視，則表示與此主流經典相對應之心理需求度也愈高；而這種心理需求，很可能就是主導大乘起源與開展的原動力。其次，筆者從初期大乘經典中，找出了它們基本的思想型態──發菩提心、修菩薩行而成佛；而且又在後期大乘的《勝鬘經》、《究竟一乘寶性論》和《大乘起信論》中，發現有足以作為大乘發心形上基礎的「佛性清淨正因」和「真如熏習」的說法。 從心理學、宗教學和神話學的觀點來看，這種大乘發心的思想原型，正反應了人類普遍「渴望無限」、「追求超越」、「嚮往圓滿」的深層心理需求。而這種由避苦求樂之生命本能提升而成的最高心理需求，正是釋尊圓滿成佛的導因，也是世界各大宗教向上發展最主要的內在動力。因此，以佛弟子集體潛意識中欲倣效佛陀、追求超越、嚮往圓滿的心理需求作為大乘起源與開展之原動力，應該是非常恰當的。當我們把這種深層心理需求作為主要的思考角度來探討大乘興起的問題時，「佛滅後，佛弟子對佛的永恆懷念，對舍利的建塔供奉，以及有關佛的本生、譬喻、因緣和十方淨土、十方現在諸佛菩薩等教典的流傳」，乃至於「大乘之天化」、「如來藏思想」和「念佛法門」等大乘起源與開展的種種現象，才會呈現出如本文所闡明的另一種更深刻、更正面的意義。

　　　　　In two of his major works, The Origin and Development of Early Mahaayaana Buddhism and An Intellectual History of Indian Buddhist Thought, the elder master Yin-shun regarded "the fact that the Buddha's disciples remembered him forever after his death" as the original force through which the Great Vehicle arose and developed. Though the proofs he adduced do not seem sufficient to establish his theory, it became widely accepted by the scholarly community in Taiwan. Thus the present writer tries to introduce a new approach by looking into the deep levels of the human collective subconsciousness to find the psychological factor behind the rise of the Mahaayaana. The present writer first formulates the hypothesis that the ideological format of the early Mahaayaana scriptures corresponded to the psychological needs of the Buddhist practitioners, i.e. it was a reflection of spiritual requirements when the texts of a certain ideological persuasion increased in number and gained in importance until they constituted the mainstream. It is well possible that these psychological needs were the driving force behind the origin and development of the Great Vehicle. Next, the present writer identifies the common thought patterns in early Mahaayaana texts: the development of bodhicitta, the practice of the bodhisattva path, and the accomplishment of buddhahood. In later Mahaayaana scriptures─the `Sriimaalaasuutra, the Ratnagotravibhaaga, and the Ta-sheng ch’i-hsin lun─ideas like “the buddha nature which is the pure cause" or "transforming influence of suchness" are found which served as the metaphysical basis for the development of a Mahaayaana frame of mind. Looked at from the angles of psychology, religious studies, and mythology, this archetypal Mahaayaana motivation reflects the deep human spiritual need of "boundless hope", "striving for transcendence" and "yearning for perfection." These most exalted psychological needs, the sublimation of the life instinct which strives to avoid suffering and attain happiness, were the causes that lead Sakyamuni to the realization of perfect awakening. They are also the main inner force behind the development of the major world religions. Thus it seems to be most appropriate to regard the collective subconscious desires of Buddhist practitioners, i.e. the wish to emulate the buddha, to strive for transcendence and to yearn for perfection, as the main factor originally leading to the arising and development of the Greater Vehicle. As soon as we begin to analyze the question from this point of view, many phenomena related to the beginnings and the subsequent development of the Mahaayaana, like "the fact that the Buddha's disciples remembered him forever after his death, the construction and veneration of stupas as well as the spread of scriptures which deal with life stories of the Buddha and of disciples or introduce the pure realms or the buddhas and bodhisattvas in the ten directions," even "the theistic trend within the Mahaayaana," "the idea of a tathagatagarbha" and "the practice of being mindful of the Buddha", acquire a new, more basic, more profound, more positive meaning.