In mid-17th century Czar Alexei Mikhailovich and his closest confidants found themselves at the crossroads. Medieval Russia turns out to be increasingly obsolete against achievements of the West. The church reform was conceived for «moral correction» of ecclesiastic affairs. Learned monks headed by Epiphanius Slavinetzki were invited to Moscow to carry out the conceived program. However the Czar was utterly dissatisfied with Greeks and in 1660s invited «Latinists», graduates of Kievo-Bratski college. Simeon Polotzki was the leader of this group. The struggle for the spiritual predominance at the Czar’s court between two trends («Greek» and «Latin» ones) gradually transformed into the struggle for the future cultural position of Russia. The author investigates epistemological aspect of the confrontation. According to the author, two discourses are revealed in texts and documents of that epoch. One discourse is predominantly allegoric while the other one is syllogistic. The first discourse was embedded in the Russian medieval ecclesiastic and popular tradition. The other discourse was brought in by the «Latinists» ands represented «new thinking» of a sort. The power which desperately needed church people and officials who were able to think clearly gradually leaned towards the second discourse. This discourse allowed Russian intellectuals in the next, 18th century to fall into dialogue with Enlightenment and to implement the basic reception of the European philosophy of the Modern time.