Ludwig Wittgenstein's Remarks on Colour opens with an example of two language games: reporting whether a certain body is lighter or darker than another; and stating the relationship between the lightness of certain shades of colour. Wittgenstein draws an analogy: this is like comparing the lengths of two sticks and the relationship between two numbers. The form of the language game is the same: ‘X is lighter than Y’. But in the first, it is an external relation and the proposition is temporal; in the second it is an internal relation and the proposition is timeless (Wittgenstein 1978: 2).