Quotes of the day 19th January 2022


Thomas Sowell describes one of the problems with assuming that current and past trends will simply carry forward very effectively in the quote above: another expression of the same principle was given by the Economist magazine a few years ago when they wrote of forecasts derived purely from extrapolation, 

"Beware of optimists with rulers!"

A rather longer and whimsical, but amusing, reductio ad absurdum against the idea that it is safe to forecast by thoughtless extrapolation of existing trends was penned by Mark Twain nearly a hundred and forty years ago in "Life on the Mississipi."

The Mississippi between Cairo and New Orleans was twelve hundred and fifteen miles long one hundred and seventy-six years ago. . . . Its length is only nine hundred and seventy-three miles at present.

Now, if I wanted to be one of those ponderous scientific people, and “let on” to prove what had occurred in the remote past by what had occurred in a given time in the recent past . . . what an opportunity is here! Geology never had such a chance, nor such exact data to argue from! . . .

In the space of one hundred and seventy-six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over one mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oolitic Silurian Period, just a million years ago next November, the Lower Mississippi River was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-rod. And by the same token any person can see that seven hundred and forty-two years from now the lower Mississippi will be only a mile and three-quarters long. . . . 

There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.”

You can find the full quotation in context here.



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