The wax argument or the ball of wax example is a thought experiment that René Descartes created within his Meditations on First Philosophy. He devised it to analyze what properties are essential for bodies, show how uncertain our knowledge of the world is compared to our knowledge of our minds, and argue for rationalism.
Descartes first considers all the sensible properties of a ball of wax such as its shape, texture, size, color, and smell. He then points out that all these properties change as the wax is moved closer to a fire. The only properties that necessarily remain are extension, changeability
photo by Talia Shulze November 2018 Teotitlan De Valle, Oaxaca, Mexico