In our highly technological society we cannot do without experts. We accept this fact of life, but not without anxiety. There is much truth in the definition of the specialist as someone who “knows more and more about less and less.” But there is another side to the coin of expertise. A really great idea in science often has its birth as apparently no more than a particular answer to a narrow question; it is only later that it turns out that the ramifications of the answer reach out into the most surprising corners. What begins as knowledge about very little turns out to be wisdom about a great deal.
So it was with the development of the theory of probability. It all began in the seventeenth century, when one of the minor French nobility asked the philosopher-scientist Blaise Pascal to devise a fair way to divide the stakes in an interrupted gambling game. Pascal consulted with lawyer-mathematician friend Pierre de Fermat, and the two of them quickly laid the foundation of probability theory. Out of a trivial question about gambling came profound insights that later bore splendid fruit in physics and biology, in the verification of the causes of disease, the calculation of fair insurance premiums, and the achievement of quality control in manufacturing processes. And much more.
The service of experts is indispensable even if we are poor at ascertaining under which circumstances they add value, when they add noise, and when they are harmful. Hardin cautions that each new expertise introduces “new possibilities of error.”
“It is unfortunately true that experts are generally better at seeing their particular kinds of trees than the forest of all life.”
— Garrett Hardin
Thoughtful laymen — that's us — can, however, “become very good at seeing the forest, particularly if they lose their timidity about challenging the experts. … In the universal role of laymen we all have to learn to filter the essential meaning out of the too verbose, too aggressively technical statements of the experts. Fortunately, this is not as difficult a task as some experts would have us believe.”
Filters Against Folly is Hardin's attempt “to show there …. (are) some rather simple methods of checking the validity of the statements of experts.”