At the beginning of The Order of Things Michel Foucault (1974) refers to an ancient Chinese encyclopaedia cited in a short story by the Argentinean writer Jorge Luis Borges. The story is ‘The Analytical Language of John Wilkins’ and the encyclopaedia is entitled the Celestial Emporium of Benevolent Knowledge. It contains the following taxonomy of the animal kingdom:

(a) those that belong to the Emperor; (b) embalmed ones; (c) those that are trained; (d) suckling pigs; (e) mermaids; (f) fabulous ones; (g) stray dogs; (h) those that are included in this classification; (i) those that tremble as if they were mad; (j) innumerable ones; (k) those drawn with a very fine camel’s hair brush; (l) others; (m) those that have just broken a flower vase; (n) those that resemble flies from a distance.

(Foucault 1974: xv) Now consider the following excerpt from The Child’s Conception of the World (Piaget 1929), where Piaget talks to Roy, age six, about the origins of the sun and the moon. Roy’s answers are in italics.