[In science any model depends on a pre-chosen taxonomy] a set of classifications into which we divide the enormous complexity of the real world... Land, labor, and capital are extremely heterogeneous aggregates, not much better than earth, air, fire, and water.

Boulding (1986) "What Went Wrong with Economics?" in: The American Economist Vol 30 (Spring) pp. 7-8, as cited in: Deirdre McCloskey (2013) "What Boulding Said Went Wrong with Economics, A Quarter Century On"