The Wax Symbol Analysis

In a famous thought experiment from the Second Meditation, the Meditator uses a piece of wax to represent why the senses cannot truly perceive the essence of things—and why pure reason can. He imagines the wax’s sensible qualities—like its color, shape, and texture—but then imagines putting it by the fire so that it softens. Now, instead of being solid and cold, the wax is soft, warm, and easy to mold. It could be manipulated into infinite different shapes. Eventually, after enough heating, it even turns into a liquid. But the whole time, it’s always the same wax. This proves that the wax’s qualities that humans can perceive with their senses do not accurately capture the wax’s true nature. Instead, the senses only give us an “imperfect and confused” perception of the wax’s reality, and truly knowing the wax’s fundamental essence requires understanding it with the intellect. The wax’s real nature is to be “a certain extended thing which is flexible and movable.”

This thought experiment brings the Meditator to the principle at the core of Descartes’s epistemology, or theory of knowledge: true knowledge comes from rational understanding, and the senses only give us imperfect information. In fact, this is similar to how modern scientists might say that an object’s true nature depends on its chemical composition, and not on the way it looks in any given state. Of course, this makes sense, since Descartes’s rationalist method—in which he argues that all true knowledge begins with rational insight—is the foundation for most science today.