Page:Hull 1900 Petty's Place in the History of Economic Theory.djvu/12

318 even to so energetic and resourceful a man as Petty; and, while he repeatedly demanded governmental assistance in his quests, his eagerness for results too often led him to resort, in the absence of specific facts, to calculations that were nothing more than guesses. Whenever he took time to consider them, he recognized keenly enough their conjectural character. "I hope," he writes to Aubrey, "that no man takes what I say about the living and dying of men for a mathematical demonstration." But, when the afflatus was on him, he was prone to take what he said for a mathematical demonstration himself. He did not hesitate to advance, in all seriousness, the most astounding proposals for increasing the national wealth of the three kingdoms by a wholesale deportation of the Irish and Scotch into England,—proposals based solely upon the results of a complicated series of guesses and multiplications. Still, we may not condemn him without mitigation. He was a beginner; and his mistakes in method, if not in advocacy, are not without their modern analogies. The neatness with which industrial facts can be represented by the use of mathematical terms, integral, symbolic, or graphic, carries undeniable advantages for purposes of analysis. It helps to keep ideas distinct and uniform. It throws light upon their possible permutations and combinations. But this very neatness has its dangers. The mistakes of political arithmetic may be repeated by sociological geometry and economic calculus. An investigator may fancy his problem solved when it is merely restated in a new form. The new and neater form may be a step toward eventual solution. Achieved solution it generally is not.

The influence of the statistical method, as exemplified in Graunt's Observations and in Petty's writings, can be traced