Here, then, was the sprouting of modern civilization—the beginning of that specializing of each man in his own particular direction that has carried the world to its present high state of expertness in so many fields. Slowly steadily, and inevitably this principle of specialization has been developed. With the increase of laws, for example, certain men came to give them special study and then to sell their knowledge and skill to other men who had no opportunity for such study. In course of time, the aggregation of laws became so great that these lawyers were forced to specialize among themselves; to-day, therefore, we find a number of classes of law specialists. The same thing is true of doctors who have limited their practise until we find those who treat the eye only, or the lungs, the stomach, or the teeth. Even the treatment of the teeth has been subdivided, some dentists limiting themselves to extraction and some of them even to the treatment of a single disease of the gums. Engineering, too, has branched like a tree and the branches have branched again and yet again. Electrical engineering has come to be divided into so many departments that telephone companies employ specialists in many branches of the engineering profession. We find the same conditions in any field of thought or activity—all commercial and industrial life is divided and subdivided; labor is specialized; writing is specialized; teaching is specialized; even warfare has become a contest between many kinds of trained specialists, each employing the tools of his trade; and every man's outlook upon life is directed chiefly toward the particular corner of the particular field that he has fitted himself to occupy. The first step toward this complex condition of the modern world was taken when each man stopped getting his own food, making his own weapons, and providing for all his individual wants without dependence upon others. When he learned to exchange that which he could best produce for that which some other man had learned to make better than he, the human race unconsciously turned away from the status of the birds and the beasts and began the long, slow upward climb that history records. It was, then, through trade, barter and exchange that man began to acquire the manners of civilized life. Trade itself became a specialized activity, and dealers who did nothing but buy and sell, but themselves produced no material goods, found that a special calling was rightfully theirs. The modern merchant is the heir of one of the first "specialists" in human activity, and the misunderstood work of the so-called "middleman" is one of the bases of modern civilization—a necessary and honorable calling. [Illustration: THE FIRST RECORDED SUN DIAL _The "Dial of Ahaz" was probably a flight of curving steps upon which a beam of sunlight fell. See Isaiah, xxxviii._]