幾千年來人類對哲學本體實相的探索與描述，特別是西方的科學哲學家們，一直在努力從事，但迄今仍無具體明確的成果. 本文先定義出心理狀態的不二境界及其相關性質. 基於此境界我們從科學觀點提出哲學本體實相的四個層次，即宏關層次，微觀層次，理念層次及終極實相層次. 對哲學本體實相我們已然作出了具體明確的描述. 比較這終極本體實相與不二境界我們提出這二者是等同的. 很多佛教哲學家們對[心物一元論] 這個名辭常會感到困擾. 很明顯地[心] 與[物] 是兩種不同的基本[東西] ，怎麼能將這二者稱為一元呢? 為要解釋這 [心物一元論] 的困惑，我們用上述實相的四個層次來細看這個問題. 在宏關層次裡，心與物都存在，實相的描述應是[心物二元論] ; 在微觀層次裡，實相的描述應是[心能二元論] ，因[物質] 已不是基本單元，而[能量] 可以概括地包含物質; 在理念層次裡，應可以用[唯心論] 來做描述; 最後在終極實相層次裡，實相的描述應是[超越一元論] . 總合地說，包含我們自己在內的整個宇宙可以簡單地說為[心物一元論]. 這種描述法同時描述現象世界與本體：描述現象部分的可觸知現象世界是[心]與[物]，而描述本體部分的終極實相是一元論或超越一元論. For thousands of years the search and description of philosophical noumenon or ultimate reality has been undertaken by human beings, it still has not been clearly and distinctively succeeded. In this paper we approach the problem by firstly defining the no-two state of mind and its relevant properties. Then from scientific point of view we propose for the philosophical noumenon or reality a structure of four levels. These four levels are the macroscopic or sensual level，the microscopic or science level，the mathematical or reasoning level，and the noumenal or ultimate reality level. It can be seen from this 4-level scheme that the no-two state of mind is equivalent to the ontological noumenon or ultimate reality. Another theme of this paper is to claim that the ontological noumenon or ultimate reality is equivalent to Buddhist nirvana. Stating those features, especially the four virtues of nirvana, one can see that the nirvana state is equivalent to the no-two state of mind. Consequently，the ontological noumenon or ultimate reality，the no-two state of mind，and Buddhist nirvana are equivalent to one another. Most Buddhist philosophers are confronted and puzzled by the wellknown Buddhist term：mind-matter monism. Clearly mind and matter are two fundamental things. How can the two things be called a monism? To resolve the mind-matter monism puzzle we also employ the 4-level approach, which means to look into the problem via our 4-level scheme. In the macroscopic or sensual level，both mind and matter exist. Reality in this level should be mind-matter dualism. In the microscopic or science level，mind-matter dualism is hardly valid in the subatomic realm. This is because matter becomes waves and no longer exists like matter. One may speak of it as mind-energy dualism in this level. In the mathematical or reasoning level，only thoughts or consciousness exists. One should have spiritualism. The phenomenal world is superficial and stems from the single entity?mind. In the noumenal or ultimate reality level，the no-two state of mind is transcendental and mystic and provides^the ultimate home for an individual. One may call it transcendental monism，or simply monism. Within the academic realm one may simply say that the whole of his universe including himself be described by mind-matter monism. It covers both the phenomenology and ontology，implying that Phenomenally our tangible reality is mind and matter while ontologically the ultimate reality is monism.
