Traditionally, universal classification schemes attempt to enumerate and organize all knowledge within a single hierarchical structure. In the following passage from The French Lieutenant's Woman (Fowles, 1969), the construction of an enumerative classification, exemplified by the Linnaean classification of living things, is characterized as a futile attempt to fossilize the world as we know it: "Charles called himself a Darwinist, and yet he had not really understood Darwin. But then, nor had Darwin himself. What that genius had upset was the Linnaean Scala Naturae, the ladder of nature, whose great keystone, as essential to it as the divinity of Christ to theology, was nulla species nova: a new species cannot enter the world. This principle explains the Linnaean obsession with classifying and naming, with fossilizing the existent. We can see it now as a foredoomed attempt to stabilize and fix what is in reality a continuous flux, and it seems highly appropriate that Linnaeus himself finally went mad; he knew he was in a labyrinth, but not that it was one whose walls and passages were eternally changing." Why would the attempt to represent all knowledge (or all knowledge of a single, broad domain, such as the realm of living things) within a single hierarchy be so unfeasible and/or impracticable as to drive Linnaeus mad?