〈雙重尋道論〉：「主客對立」與「天人合一」之對立與合一

The Dual Tao-Searching Theory: The Unification and Opposition of ''Unity of Humans and the Universe'' and ''Separation of Subject and Object''

人活在世間，總是在追尋某種人生終極價值或生命境界，而東、西方文化場域各自提供兩條道路：西方是藉由「何物道路」通往客觀真理和自我實現，東方則是依循「何去何從道路」走向天人合一和無我境界。本研究遵循「一種心智，多重心態；普世主義，考量分疏」（Shweder et al.,1998）的研究原則，另以陰陽論和佛家依存主義作為本體論預設，再以黃光國（2011）的先驗形式結構〈自我曼陀羅模型〉作為研究框架，並以Goodale與Milner（1992）「大腦雙重路徑假說」作為立論基礎，建構〈雙重尋道論〉，試圖說明原屬同一個心智的生物性「個體」，如何展現不同心態而形成「現實我」，再進而向上提升至「理想我」，並且分析東、西方文化所持的形上預設為何，以及各自所追尋的人生終極價值和生命境界為何。本研究聯繫本土心理學和神經科學，希望能對本土心理學乃至整個本土社會科學所面臨的黃光國難題，提供另一種解套思維。

The meaning of human life is about the pursuit of ultimate value and attainment of the highest state of being. Eastern and Western philosophies each provide a method of reaching these goals based on their particular metaphysics. Western cultures utilize the way to what-Tao to achieve objective truth and self-realization. Eastern cultures utilize the way to how-Tao to achieve unity between humans and the universe (天人合一) and anatman (無我; selflessness or nonself). Tao means the way, the road, the truth or ultimate value. I propose the dual Tao-searching theory to depict this phenomenon and elucidate the nature and neural basis of these two approaches. Buddhism and ying-yang ontology provide the ontological basis for my arguments. I apply K. K. Hwang's Mandala Model of Self as described in the transcendental formal structure as a general research framework. To construct the dual Tao-searching theory, I used Goodale and Milner's two-streams hypothesis, which attempts to explain how an individual with one mind can have two mentalities that become the actual self, and then this actual self can be sublimated into the ideal self. I also analyze the metaphysical presuppositions of Eastern and Western cultural views and how they shape the relationship of human beings with the divine, Nature, and the secular world. In addition to constructing a theory, I also propose several feasible investigative research programs. The core concept of the dual Tao-searching theory is that the ultimate values implied by Eastern and Western metaphysical presuppositions correspond to the neural basis of the how pathway and the what pathway, respectively, as described by Goodale and Milner's two-streams hypothesis. Eastern cultures emphasize the way to how-Tao, the neural basis of which is the how pathway involved in the dorsal stream. Western culture emphasizes the way to what-Tao, the neural basis of which is the what pathway involved in the ventral stream. The Eastern way to how-Tao metaphysically focuses on unity between humans and the universe, the interdependence of all things, holism, a dynamic viewpoint, naturalism, and internal control or self-modification. Of these, the most important is unity between humans and objects, which is the essence of the dorsal stream how pathway. The Western way to what-Tao metaphysically focuses on separation between subject and object (主客對立), the self as an independent being, objects as independent entities, atomism, reductionism, a static viewpoint, anthropocentrism, and external control or dominance. Of these, the most important is separation between subject and object, which is the essence of the ventral stream what pathway. As such, I suggest that Goodale and Milner's two streams hypothesis can provide the research foundation in terms of research methods and procedures for the dual Tao-searching theory. Whereas Goodale and Milner's two-streams hypothesis portrays neuroanatomy and physiology, the dual Tao-searching theory emphasizes psychological and cultural aspects of being. Neuroscience is the current trend. Researchers in almost every discipline relate their work to neuroscience, sometimes even creating a new field (e.g., neuroesthetics, neuroeconomics, social neuroscience, or cultural neuroscience). However, indigenous psychologies seldom address the field of neuroscience. If psychologists are to follow the research principle of ''one mind, many mentalities; universalism without uniformity'' proposed by Richard Shweder, they need to consider biological aspects when discussing the one mind. This concept is the same as that described by Hwang's Mandala Model of Self in relation to the concept of individual. I connect indigenous psychologies with the study of neuroscience with the hope of creating a new frontier in Chinese indigenous psychology, and to provide a tentative resolution to K. K. Hwang's grand question of how to integrate the seemingly conflicting metaphysical perspectives of unity between humans and the universe (Eastern cultures) and separation between subject and object (Western cultures).