哲學的分支，其目的在於確定事物的真實本質，確定存在物的意義、結構和原理。在西方哲學史上，對形上學有四種看法：一、是對存在物（如精神和物質）的探求；二、是一種「實在」的科學，與「表象」相反；三、是對世界整體的研究；四、是第一原理（或本體）的理論。形上學的字面意義是「物理學之後」，曾被用於指亞里斯多德着作中亞里斯多德自稱的「第一哲學」那部分。亞里斯多德已為哲學家區分了兩種任務：研究自然界以及存在於自然界和理性世界的特性，以及探求「存在」以及不動的物質、「不動的行動者」的特點。前一條組成「第二哲學」，主要在他的《物理學》中論述；第二條也叫做「神學」（因為上帝是不動的行動者），在其着作《形上學》中有論述。
metaphysics
Branch of philosophy whose object is to determine the real nature of things, to determine the meaning, structure, and principles of whatever is insofar as it is. In the history of Western philosophy, metaphysics has been understood as: (1) an inquiry into what sorts or basic kinds of things (e.g., the mental and the physical) exist; (2) the science of reality, as opposed to appearance; (3) the study of the world as a whole; and (4) a theory of first principles. The term means literally “what comes after physics,” and was used to refer to the contents of Aristotle's treatise on what he himself called “first philosophy.” Aristotle had distinguished two tasks for the philosopher: to investigate the nature and properties of what exists in the natural, or sensible, world, and to explore the characteristics of “being as such” and inquire into the character of “the substance that is free from movement,” the unmoved mover. The first constituted “second philosophy” and was carried out primarily in his Physics; the second, which he also called “theology” (because God was the unmoved mover), is discussed in his Metaphysics.
