心之不可化約性問題(the Problem of the irreducibility of mind)又稱為意識的問題，意指「心靈概念無法化約於物理概念」，簡單的說就是，「客觀物理概念無法用來完全說明主體心靈現象」。這個問題可說是當今西方哲學界最熱門的話題之一，自從笛卡兒提出心物二元論之後，心物問題(mind-body problem)就一直困著許多偉大的思想家，如今心物問題的研究找到了其核心點，這個核心點就是意識的問題，尤其在當今腦神經科學突飛猛進的時代，這個問題更顯示其重要性。本文的主要目的是對這個問題本身作詳細的分析與說明，並且介紹當今主要的理論學派。

The problem of the irreducibility of mind, also known as the problem of consciousness, refers to “the irreducibility of the concepts of mind into the concepts of physics.” In short, “the objective concepts of physics are incapable of explaining completely the subjective phenomena of mind.” This is one of the most popular topics in the western world of philosophy. The mind-body problem has puzzled many great thinkers, ever since Descartes introduced the mind-matter dualism. Now the study of the mind-body problem has found its core to be the problem of consciousness, which seems to be more important nowadays when brain science is progressing quickly. The purpose of this paper is to make a detailed analysis and explanation about this problem and introduce the major academic schools in this field.