These dangers were patent; they resulted from the existence of privileged classes or hereditary aristocracies, of State religions, censorship of the press and books, centralization and concentration in a few hands of all the financial and economic resources of the country. Anything that smacked of the European system was to be fought with the utmost energy, not only for the sake of America, but for the sake of the world. Such were the real reasons that justify the fight waged by Jefferson after his return from Europe against the tendencies represented by Hamilton. Not out of any sympathy for the Jacobins did he seem to favor the French Revolution; but, since America herself had become the battlefield of two opposed ideals, he sided with the one which, in his opinion, presented the smaller danger for the existence of his country. Throughout the long-drawn-out battle, he remained convinced that only by avoiding any entanglement with European politics could America fulfill her destiny. The great obstacle to such an isolation was foreign commerce, for Jefferson clearly understood that economic and commercial bonds or dependence would necessarily entail political bonds and political dependence. America was to live in her own world, to pay her debts as soon as possible, to become industrially independent of Europe, to manufacture at home enough for her own consumption "and no more." She was also to seize every opportunity to eliminate dangerous neighbors, not that she really coveted any territory or colony held by foreign powers, not that she needed new land for a surplus of population; but she could not keep out of European politics if Europe remained at her doors and used her colonies as a "fulcrum for her intrigues." Spain was so weak that nothing had to be feared directly from her, but her colonies could be seized at any time by more powerful enemies; France should not be permitted again to set her foot on the American continent. As to England, she was to be expelled from her continental dominions whenever America would be strong enough to enforce the "_American jus gentium_", and the sea was to be neutralized.