A universal history is fitted to correct such defects as may be incident to that extreme specialism in historical writing which is now in fashion. The broad and concise treatment which a history of all times and peoples must adopt naturally leads to efforts to characterise the dominant features and tendency of an epoch or a movement, whether social, economic, or political. [Sidenote: The Side Streams of History] Yet even here there is a danger to be guarded against. No epoch, no movement, is so simple as it looks at first sight, or as one would gather from even the most honest contemporary writer. There is always an eddy at the side of the stream; and the stream itself is the resultant of a number of rivulets with different sources, whose waters, if the metaphor may be extended, are of different tints. Let any man study minutely a given epoch, such as that of the Reformation in Germany, or that of the Revolutionary War in America, and he will be surprised to find how much more complex were the forces at work than he had at first supposed, and on how much smaller a number of persons than he had fancied the principal forces did in fact directly operate. Or let any one--for this is perhaps the best, if the most difficult, method of getting at the roots of this complexity--study thoroughly and dispassionately the phenomena of his own time. Let him observe how many movements go on simultaneously, sometimes accelerating, sometimes retarding, one another, and mark how, the more fully he understands this complex interlacing, so much the less confident do his predictions of the future become. He will then realise how hard it is to find simple explanations and to deliver exact statements regarding critical epochs in the past. [Illustration: Mercier THE FIRST INDUSTRIES: POTTERY From the painting by Ferdinand Cormon ] [Illustration: Mercier THE FIRST INDUSTRIES: THE FORGE From the painting by Ferdinand Cormon ] [Sidenote: The Main Stream of History]