Yet everyone in Moscow who went from one Church to another was well aware that during the ages there had occurred mistakes in the Church books, errors of copying, slight interpolations, even cases of corruption which destroyed the sense of the passages. What was to be done? The recognition of the need for some correction of the books was blocked by the impossibility of accepting any standard for the work. For nearly a century there went on a sterile debate on the subject and at the end of that time there was still no agreement as to the texts which should be taken as models. The nationalistic Muscovite leaders absolutely refused to accept any Greek texts, even though it was generally agreed that the Church Slavonic services had been translated from the Greek, for in their eyes the fall of Constantinople had seriously damaged the Orthodox character of even the oldest Greek texts and it was beneath the dignity of the Third Rome to learn from outsiders. As the last and greatest of these leaders, Avvakum, proudly declared at his trial before the Eastern Patriarchs in 1666, it was their duty to come and learn from Moscow rather than to pass judgment upon any Muscovites, for they alone possessed the true faith and a Christian and Orthodox autocrat. It is impossible to overemphasize this ingrown character of Muscovite culture and thought in the sixteenth century. Xenophobia was the order of the day and even such a tsar as Ivan the Terrible who allowed Germans and other foreigners to come in small numbers to Moscow could not defy the will of the boyars and the masses and accept foreign ideas. The Troublous Times that followed the death of Boris Godunov and saw the occupation of the Kremlin by a Polish army showed, however, to some of the intelligent Muscovites that all was not well at home. They realized that Moscow would sooner or later be compelled to accept some elements of Western and contemporary culture or the state would be in serious danger. They realized that it would be impossible to make progress at the expense of Poland and Lithuania, if they maintained this deliberate exclusion of all foreign ideas, and a steadily increasing number of men determined in one way or another to change the situation. The leading spirit of this group was Nikon, who was destined in 1652 to become the Patriarch of Moscow. No less overbearing and haughty than had been his predecessors, Nikon was intelligent enough to know that something had to be done and done rapidly, if disaster was to be averted and in this he had the sympathetic backing of Tsar Alexis.