§7. _The Trade Cycle_. But our reference to trade depressions suggests a final comment on Law II. One small qualification was embodied in our original statement of it, namely the words "sooner or later." A rise in price may not check the demand immediately (even if the printing presses are standing idle in the Treasuries); it may actually stimulate it for a time. For people may fear that the price will rise further still, and hasten to buy what they _must_ buy before very long. Sellers may share the same opinion, and be reluctant on their side to part. When prices are falling the roles are reversed, and we are likely to see the sellers tumbling over one another in a frantic eagerness to sell, the buyers wary and aloof. Sooner or later, indeed, these tendencies must dissolve and disappear; but they may persist for a longer period than might seem probable at first. For the raw material of one trade is, as we say, the finished product of another. The demand for one thing gives rise to a demand for other things, for the labor with which to make them, and so on in an expanding circle. A sympathy, subtle and intense, unites the business world, and a wave of depression or animation arising in any quarter may spread itself far and wide, heightened by the gusts of human hope and fear, and continue long before its influence is spent. Here we are upon the threshold of one of the most striking and formidable of economic facts, the regular alternation of periods of good and bad trade, each very widespread, if not world-wide, in its range, each comprising certain regular phases of acceleration and decay, and each infallibly yielding sooner or later to the other. The details of these phenomena are highly complex, some of them obscure; an immense literature has already been devoted to the subject, yet its systematic study is hardly more than begun. The account given in the preceding paragraph is incomplete and meagre. It is inserted here in the hope that it will impress the reader with a sense both of the fact of these alternations and of the deeply rooted nature of the causes from which they spring. They take a heavy toll of human happiness and wealth; and there is no object that more urgently calls for concerted human effort than that of mitigating them, and of alleviating the misery which they bring in their train. Still better, of eradicating them if that is possible; but let none suppose that it can be lightly done. Meanwhile, let us always remember that they form the atmosphere and medium in which the enduring tendencies of the business world must work themselves out. It is often convenient to speak of "normal conditions" in this trade or that; but hardly ever can it be truly said of a particular moment that conditions are normal. The normal is rather a mean level about which oscillations to and fro, round and about, are constantly taking place, but which itself is reached only by accident, if at all. Whenever we say that some new factor should in