In this paper a new method of Buddhist hermeneutics, developed out of my creative hermeneutics, is implemented to critically re-investigate the origin and gradual formation of the doctrine of dependent origination (Pratityasamutpada),as well as further development of the doctrine in the `Mahayana` Buddhist tradition. At the first hermeneutical stage ("What exactly did the original thinker or text say?"),I discuss the results of research by Japanese Buddhist scholars (such as Nakamura Hajime and Saigusa Mitsuyoshi) on the earliest existing texts documenting the origin and formation of the doctrine of dependent origination,and conclude that there is no conclusive evidence showing that the "twelve-link" theory was clearly formulated either in Buddha's time or immediately after his demise (Parinirvana). At the second hermeneutical stage ("What did the original thinker or text mean to say?"),I discuss the heated debate between two groups of Japanese Buddhist scholars over the original meaning of "dependent origination," suggesting that the academic unresolvability of the textual/hermeneutic problem leads us to the third stage ("What could the original thinker or text have said and implied? "). Here I investigate the philosophical grounds for the major Hinayana and `Mahayana` theorizations of the doctrine,including Sarvastivada's theory of "dependent origination in terms of karma-influences, " Madhyamika's theory of "emptiness of (the self-nature of) dependent origination," Yogacara's theories of "three natures and three non-natures" and "dependent origination in terms of alaya-consciousneness, "the theory of "dependent origination in terms of the Womb of Buddhahood (tathagata-garbha),"Hua-yen's theory of" dependent origination in terms of Dharmadhatu, Shingon's theory of "dependent origination in terms of the Six Greats, " and Zen Master Dogen's theory of "(the presencing of) being-time (uji)." At the fourth stage I attempt to "dig out," so to speak, the deep structure underlying the surface structure of the pratityasamutpada thought in its various forms. I conclude that this central concept of Buddhism,if creatively interpreted and developed, has enormous ontological/ethical/aesthetic/psychotherapeutic significance in a contemporary context.