What is the “Physical”? The Problem of Defining the Concept of “Physical” in the Mind-Body Debate

Abstract

According to contemporary physicalism, everything in the world has physical nature. However, it is far from clear how exactly we should understand the concept of “physical”. Although today's physicalism is the intellectual heir of traditional materialism, with the development of physics, the traditional concept of materiality has become outdated. On the one hand, it seems we must not commit ourselves independently of empirical researches to any a priori definition, and this, on the other hand, threatens to empty the thesis of physicalism.

In this article, I will exhibit the contemporary attempts to define the concept of “physical”, along with the arguments for and against them. I will treat the so-called theory-based solutions, which allude to physical theories to the definition of “physical”. I also present the solutions built upon paradigmatic examples and the so-called via negativa theories. The former tries to define the concept through objects that are typically considered physical in everyday life, while the latter through mental phenomena. At the end of the essay, I try to explain the failure of the attempts to define the concept by distinguishing two different meanings of physicalism.