From Bolivar: American Liberator, by Marie Arana (Simon & Schuster, 2013), Kindle p. 65:
In the elegant bustle of the Humboldt villa in Rome, however, the diplomat Wilhelm von Humboldt introduced Bolívar to Antonio Vargas Laguna, Spain’s ambassador to the Holy See. Vargas would later be imprisoned for his harsh and principled views of Napoleon, but in those early and heady days of 1805, when tolerance was the rule and France was perceived to be a progressive force in the world, the candid ambassador was a highly respected presence. In a fit of generosity, he offered to take Bolívar to the Vatican to meet Pope Pius VII.
Perhaps Vargas thought he had prepared his young guest adequately when he told him that a visitor to the pope should be ready to kiss his sandal and pay deference to papal symbols. But the ambassador was rudely surprised by the scene that unfolded under his supervision. When they were ushered into the papal offices and Bolívar was expected to step forward, kneel, and kiss the cross on the pontiff’s sandal, he refused to do it. Vargas was taken aback, visibly flustered. The pope, seeing the diplomat’s embarrassment, tried to make light of it. “Let the young Indian do as he pleases,” he murmured. He extended a hand and Bolívar took it and kissed his ring. The pope then asked him a question about the Indies and Bolívar answered it to his satisfaction, after which the audience was over and the pope moved on to someone else. As they were leaving the Vatican, Vargas scolded the young man for not following the proper etiquette, to which Bolívar had the sharp retort, “The Pope must have little respect for the highest symbol of Christianity if he wears it on his sandals, whereas the proudest kings of Christendom affix it to their crowns.”
It is hard to know what was more irksome to Bolívar at that moment: being expected to kiss a shoe or being rebuked by a Spaniard. He had been away from Spain’s sphere of influence for almost a year now and the distance had been clarifying. He had—as Alexander von Humboldt would come to realize many years later—a deep-seated hatred for Spain. It had started as a natural Mantuano [white Creole elite] response and had grown in the few months he had spent in Venezuela as a married landowner, struggling to manage his properties. It had grown again in France, where he had seen the exuberance of a nation rid of its Bourbon king.