The Sun Shines on William Petty
Mother Nature may have smiled upon William Petty, whose maturity coincided with a short, but welcome break in the Little Ice Age. Shortly before Petty's death in 1687, the cold weather returned. For example, the winter of 1683‑4 was particularly harsh (Lamb 1982, p. 223).
Today, when the threat of global warming looms large, people might be more sensitive to the profound effects of the weather. In earlier periods of cold weather created equally harmful results. One long‑term study of the effects of weather over the centuries concluded: "cooling impeded agricultural production, which brought about a series of serious social problems, including price inflation, then successively war outbreak, famine, and population decline successively. The findings suggest that worldwide and synchronistic war‑peace, population, and price cycles in recent centuries have been driven mainly by long‑term climate change" (Zhang et al. 2007, p. 19215).
David Hackett Fischer's The Great Wave: Price Revolutions and the Rhythm of History paints the stark picture of the times of Petty's youth:
"Famine, pestilence, and economic depression were accompanied by war. During the entire century from 1551 to 1650, peace prevailed throughout the continent only in a single year 1610. These conflicts were remarkable not only for their frequency but also their ferocity."
"During the early seventeenth century, the armies of Europe reached their largest size since the Roman era. Their upkeep imposed heavy costs at the same time that public revenues were reduced by the combined effect of famine, pestilence, war, depression, regressive taxation and monetary inflation. They also were put to use in most of Europe." [Fisher 1996, pp. 96‑97]
Fisher went on to add: "The greatest works of literature, painting, philosophy and theology in this era commonly expressed a mood of increasing pessimism and despair" (Fisher 1996, p. 100). During the second half of the Seventeenth Century, conditions were improving grain prices tended to fall (Fisher 1995, p. 105).
None of this is meant to suggest that the world suddenly became a comfortable place of peace and prosperity. The winter of 1683‑4 was particularly cold. In addition, Petty's own work with the Royal Society was closely associated with preparing for military adventures. Some of his later writings suggested that the prospects for war with France were favorable. And finally, an optimistic belief in progress was not unknown during the cold period. Samuel Hartlib, Petty's own promoter was a case in point.
Nonetheless, the optimistic swagger of Petty's proposals fell on more fertile ground as future prospects were looking better. More broadly, economic thinking tends to follow one of two paths. First, some give an ideological justification of the status quo, arguing that what is happens to be the optimal arrangement for now and for the future. Others offer proposals for improvement. At times, such as the warming mid‑seventeenth century, when new possibilities seem to be opening, such proposals are more likely to fall on fertile ground.
For example, even though Hartlib's musings about information might seem quite modern in light of the Internet, he never exercised much influence. Petty, who also had his share of far‑fetched ideas, was generally recognized as an "universal
ercised much influence. Petty, who also had his share of far‑fetched ideas, was generally recognized as an "universal genius," even by many who disagreed with him.