Descartes believed that space without matter did not exist. "If that which is in a hollow vessel were taken out of it without anything entering to fill its place, the sides of the vessel, having nothing between them, would be in contact." "The nature of matter . . . does not consist in a thing being hard, or heavy, or coloured, but only in its being extended in length, breadth and depth." What arguments do we use today to show that this concept is wrong? What is space without matter? What is the commonly accepted concept of matter?