68. If trade was an object of suspicion and dread, then indeed we ought to have _rules for distinguishing safe and beneficial trade_ from mischievous trade, but these attempts to define and discriminate only expose the folly of the suspicion. We find that the primitive men who dwelt in caves in the glacial epoch carried on trade. The earliest savages made footpaths through the forests by which to traffic and trade, winning thereby mutual advantages. They found that they could supply more wants with less effort by trade, which gave them a share in the natural advantages and acquired skill of others. They trained beasts of burden, improved roads, invented wagons and boats, all in order to extend and facilitate trade. They were foolish enough to think that they were gaining by it, _and did not know that they needed a protective tariff to keep them from ruining themselves_. Or, why does not some protectionist sociologist tell us at what stage of civilization trade ceases to be advantageous and begins to need restraint and regulation? (_B_) ECONOMIC UNITS NOT NATIONAL UNITS. 69. The protectionists say that their system advances civilization inside a state and makes it great, but the facts are all against them (see § 136ff). It was by trade that civilization was extended over the earth. It was through the contact of trade that the more civilized nations transmitted to others the alphabet, weights and measures, knowledge of astronomy, divisions of time, tools and weapons, coined money, systems of numeration, treatment of metals, skins, and wool, and all the other achievements of knowledge and invention which constitute the bases of our civilization. On the other hand, the nations which shut themselves up and developed an independent and self-contained civilization (China and Japan) present us the types of arrested civilization and stereotyped social status. It is the penalty of isolation and of withdrawal from the giving and taking which properly bind the whole human race together, that even such intelligent and highly endowed people as the Chinese should find their high activity arrested at narrow limitations on every side. They invent coin, but never get beyond a cast copper coin. They invent gunpowder, but cannot make a gun. They invent movable types, but only the most rudimentary book. They discover the mariner’s compass, but never pass the infancy of ship-building. 70. The fact is, then, that _trade has been the handmaid of civilization_. It has traversed national boundaries, and has gradually, with improvement in the arts of transportation, drawn the human race into closer relations and more harmonious interests. The contact of trade slowly saps old national prejudice and religious or race hatreds. The jealousies which were perpetuated by distance and ignorance cannot stand before contact and knowledge. To stop trade is to arrest this beneficent work, to separate mankind into sections and factions, and to favor discord, jealousy, and war.