The commercial treaties between Carthage and Rome, to which fuller reference will hereafter be made, show that if the duties levied were in some cases heavy, they were not differential or protective, but chiefly with the object of securing a sufficient revenue. That, like all commercial nations, the Carthaginians were jealous of competitors need not be doubted, but while other nations were content with profits derived from intercourse among their own people, Tyre and Carthage sought the trade of all nations and erected entrepôts where required for this commerce. At the same time, it must be borne in mind that free trade, pure and simple, as now understood, could, in ancient times, have been possible only with a very considerable modification; especially where, as was the case with Carthage and Tyre, a large portion of the dealings with barbarous nations was by barter; for competition, while tending seriously to reduce the profits, could not then have increased the demand to an extent equivalent to the reduction in price. As long as the savage is kept in ignorance, he is ready to exchange goods of great value for mere trifles, and rivalry would only serve to enlighten him as to their actual value. Moreover with uncivilized nations whose wants are limited, it is impossible to create a demand adequate to the loss accruing from open competition. Hence Carthage watched these branches of her trade with peculiar jealousy, and, while throwing wide open the harbours of the capital, closed as far as possible her colonial ports to the shipping of rival nations. It seems, therefore, unreasonable for Heeren to call the commercial policy of Carthage “paltry and selfish:”[126] for if she did guard the colonial trade which her genius and industry had created, her policy generally, as compared with that of contemporaneous nations, was as liberal as that of Great Britain now is in comparison with that of the United States of America. Carthage acted on principles of reciprocity, while her neighbours were rigid protectionists. She was ready to grant, as her treaties show, reciprocal privileges to all nations ready to deal with her on similar conditions; and on such terms, she dealt largely with Greece and with Egypt during the reign of the Ptolemies, and even with Rome. [Sidenote: Limits of trade.]