Natura Non Facit Saltum in Alfred Marshall (And Charles Darwin) (Essay‪)‬

Abstract: The adage Natura non facit saltum was, as is well known, adopted by Alfred Marshall as the motto for his Principles of Economics, most probably as a borrowing from Charles Darwin's Origin of Species. This paper examines Marshall's use of the adage and argues that, on the whole, the 'Darwinian' promise implicit in its use was not realised: his intentions to the contrary, Marshall did not adequately succeed in his objective here. Two appendices provide, first, the original uses of Natura in Darwin, and, second, a history of its (and variant) uses, including the relevant passage from Linnaeus. Introduction