What is hypokeimenon?

"Hypokeimenon" is a term derived from the Greek word "ὑποκείμενον," which means "that which underlies" or "substratum." In philosophical contexts, particularly in the works of Aristotle and later in metaphysics, hypokeimenon refers to the underlying substance or essence of a thing that exists independently of its properties or qualities. In Aristotle's ontology, the hypokeimenon is the fundamental reality that supports all attributes of an object. For example, a particular chair can have various qualities, such as color, shape, and material, but the hypokeimenon is the chair itself, the substance that possesses those qualities. The term has also been used in modern philosophy, particularly in discussions of ontology and the nature of existence, where it is sometimes associated with concepts related to substance and individual entities. In broader contexts, hypokeimenon can refer to anything that serves as a foundation or underlying basis for other concepts or phenomena.