A History of Econometrics in France From natural order to artificial worldsle Gall's

Science discovering a divinely designed world is fundamentally different from science investigating a “dappled world” ( Cartwright, 1999 ). The first world is written in elegant mathematics which describes the simple laws that rule them, the other world is too complex and messy – a “patchwork of laws” – for any unified treatment. While the first world is lighted by itself and principally transparent, the second world is much darker, so we need lanterns to have a look at it:The effort of the economist is to see , to picture the interplay of economic elements. The more clearly cut these elements appear in vision, the better; the more elements he can grasp and hold in mind at once, the better. The economic world is a misty region. The first explorers used unaided vision. Mathematics is the lantern by which what before was dimply visible now looms up in firm, bold outlines. The old phantasmagoria disappear. We see better. We see also further. ( Fisher, 1925, p. 119 )Today, these mathematical pictures are called models.