Page:Popular Science Monthly Volume 29.djvu/554

538

LTHOUGH those times have gone by which oracles and soothsayers played an important part, yet even at the present day prophets are to be found almost everywhere. We will not speak here of politicians, of those that predict peace and war, nor of speculators and the so-called reformers, with their predictions in the domain of commerce and industry. We shall confine ourselves to the discussion of natural phenomena—not alone to those that are grand and striking, but shall in preference turn to the common occurrences of everyday life.

"What weather are we to expect within the next few days?" Only put the question, and a hundred answers will be volunteered. The curing of all diseases is often predicted by quacks and patent-medicine men with a degree of assurance scarcely to be believed. "This remedy never fails," is the superfluous winding-up of many an advertisement of their nostrums, and thousands of credulous people daily fill the pockets of these charlatans.

A considerable number of those persons who do not permit themselves to be thus caught err in the opposite direction—that is to say, they regard all predictions with mistrust. For instance, they attach but little importance to any of the attainments of medical science; they doubt the usefulness of meteorological stations, etc. And yet even skeptics like these must acknowledge that numerous astronomical predictions come true with a degree of precision and accuracy that must astonish every one.

What prophecies, then, are to be believed? The predictions of science? Alas! how many supposed scientific predictions have proved to be mere delusions! The word "science" will not answer in this connection. Is there, then, no standard by which the value of predictions of natural phenomena may be gauged or measured?

A standard exists, and may be determined by an acquaintance with the elements of inductive logic, and with the most important teachings of natural science. Considering the wide-spread interest that attaches to this question, it will be worth while to study the subject a little more closely.

Almost every prediction requires some statement admitted to be universally valid, from which it may be deduced. If one desires to know how probable a prediction is, it will be well to test it by the following questions: Does the prediction rest on simple enumeration?