Note 329 — Chapter III · : THE PESSIMISTS

Turgot, Observations sur un Mémoire de M. de Saint-Péravy (Œuvres, vol. i, p. 420). “It can never be imagined that a doubling of expenditure would result in doubling the product.… It is more than probable that by gradually increasing the expenditure up to the point where nothing would be gained on the return, such items would successively become less fruitful. The earth’s fertility resembles a spring that is being pressed downwards by the addition of successive weights. If the weight is small and the spring not very flexible, the first attempts will leave no results. But when the weight is enough to overcome the first resistance then it will give to the pressure. After yielding a certain amount it will again begin to resist the extra force put upon it, and weights that formerly would have caused a depression of an inch or more will now scarcely move it by a hair’s breadth. And so the effect of additional weights will gradually diminish.

“The comparison is not very exact, but it is near enough to enable us to understand that when the earth is producing nearly all it can, a great deal of expense is necessary to obtain very little more produce.”

Turgot, with his usual perspicacity, has noted a fact which the Classical writers generally failed to perceive, namely, that at the beginning of the process of cultivation there may be a period when the return shows no signs of diminishing.